IT 214 Full Practice Midterm Exam 2

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Project yields

A vertical subset of a table

SQL character data format(s) is(are) ____.

CHAR and VARCHAR

14. Corporations use only structured data.

A dependency of one nonprime attribute on another nonprime attribute is a partial dependency.

False

foreign

It becomes difficult to create a suitable ____________________ key when the related table uses a composite primary key.

self join

It is not necessary that a ____ be based on a foreign key and a specified unary relationship

_________ represents a micro view of the entities within the ERD.

Normalization

____ yields a vertical subset of a table.

PROJECT

In-memory databases

Refer to a type of database that stores most of its data in RAM rather than in hard disks.

Unnormalized database tables often lead to various data redundancy disasters in production databases

True

Ternary Relationship

When three entities are associated. Association among 3 different entities

from

a cartesian join may be explicitly created by using the phrase cross join in the ___ statement

INSERT

adds records

A(n) ____ might be written by a programmer or it might be created through a DBMS utility program.

application program

a(n) __ might be written by a programmer or it might be created through a DBMS utility program a. query c. database management system b. operating system d. application program

application program

inner joins

are more common then outer joins

NULLIF and COALESCE

are the keywords associated with the other two forms of the CASE expression

inner join...on

are used to establish an equi-join in the from clause

ORDER BY

been used to organize the order in which the rows of output are listed

A ____ is a collection of related records.

file

Natural

optional keyword when the join is defined in the FROM clause

Lock granularity is

the detail possible with a lock

UNION clause

used to combine the output from multiple queries together into a single result table

Inner Join.. On

used to establish an equi-join in the FROM clause

exists(not exists)

used when your only interest is whether the subquery returns a nonempty(empty) set

Composite Primary Keys

useful for: - composite entities (resolving M:N relationship) - weak entities with strong relationships

Phantom read occurs

when a transaction reads data it has previously read and then finds new rows that were inserted by a committed transaction.

Recursive Relationship

when an entity is related to itself.

Data inconsistency

when different versions of the same data appear in different places.

3NF

when it includes no partial dependencies and it contains no transitive dependencies

data anomaly

when not all of the required changes in the redundant data are made successfully (update anomaly, insertion anomaly, deletion anomaly)

CAST

when performing the union command to merge, use the command to control the data conversion

Concurrent transaction

when two transactions are being processed against a database at the same time.

Full Functional Dependence

when you have all of the attributes you need for the relationship

iN (NOT IN)

when you need to know the values are (are not) in the set

FROM

where the required data is stored from___ keyword

=ALL

which makes sense only when all the elements of the set have the same value

An INNER join

will only return rows from each table that have matching rows in the other.

The EXISTS operator

will return a TRUE value if the subquery resulted in a non-empty set, otherwise it returns a FALSE

NOT EXISTS

will take a value of true if no rows are returned and false if one or more rows are returned

a(n) __ database supports a relatively small number of users (usually fewer than 50) or a specific department within an organization a. desktop c. enterprise b. workgroup d. transactional

workgroup

During the __ phase, changes are permanently applied to the database.

write

MAX

yields the maximum attribute value encountered in given column

SUM

yields the sum of all values given column or expression

The Crow's foot symbol with two parallel lines indicates ____ cardinality.

(1,1)

NoSQL

(Not only SQL) is generally used to describe a new generation of database management systems that is not based on the traditional relational database model

ERD

- Entity Relationship Diagram - Diagram that depicts an entity relationship model's entities, attributes and relations.

To remove a transitive dependency, the designer must

- Place the attributes that create the transitive dependency in a separate table - Make sure that the new table's primary key attribute is the foreign key in the original table.

Weak Entity

- The entity must be existence-dependent on its parent entity. - The entity must inherit at least part of its primary key from its parent entity.

Primary Key Characteristics

- Unique values: must be able to guarantee - Nonintelligent: no embedded semantic meaning - No Change over Time: changing value means changing identity of entity - preferrably single-attribute: minimum # of attributes possible - preferrably numeric: better managed that way - security complaint: not composed of any value that could be a security risk

Inventory has 10 counts.

- User A reduce count of item by 5 - User B reduce count of item by 3

Entity CLUSTER

- a "virtual" entity type used to represent multiple entities and relationships in the ERD. - formed by combining multiple interrelated entities into a single abstract entity object. - used to represent multiple entities and relationships with the purpose of simplifying the ERD and thus enhancing its readability.

Existent-Dependent Entity

- also known as a composite (bridge, join, link, associative) entity - generally used to transform M:N relationships into 1:M relationships.

Constraints

- are important because they help to ensure data integrity. - is a restriction placed on the data.

Cardinality

- assigns a specific value to connectivity. - expresses the of allowed entity occurrences associated with a related entity

Existence-Independent

- entity that can exist apart from one or more related entities. - created first when referencing an existence dependent table to it.

Computer fails for many reasons:

- hardware breaks- electrical power fails- programs have bugs -procedure contain errors- people make mistakes

Entity SUPERtype

- is used to minimize the likelihood of redundant relationships - s a generic entity type that is related to one or more entity subtypes - minimize the number of nulls - contains the common characteristics

Optionality

- means that one entity occurrence does not REQUIRE a corresponding entity occurrence in a particular relationship - has one or more optional relationships - represented by a O

Weak Relationship

- non-identifying relationship - exist when the PK of the related entity does not contain a PK component of the parent entity

DE-Normalization

- process which a table is changed from a higher level normal form to a lower normal form - usually done to increase processing speed - potentially yields data anomalies

Strong Relationship

- requires weak or existent-dependent entities that have primary keys partially or fully made up of the parent entity's primary key. - In a Crow's Foot ERD, a strong relationship is depicted with a solid line connecting the two entities.

Entity SUBtype

- stores data that is UNIQUE TO THE SUBTYPE

Connectivity

- symbols - describes the classification of the relationship between entities.

SURROGATE primary key

- used to ensure entity integrity, and by making queries simpler - an "artificial" PK that is used to uniquely identify each entity occurrence when there is no good natural key available or when the "natural" PK would include multiple attributes. - used to ensure that relationships between entities can be created more easily - introduced by the designer with the purpose of simplifying the assignment of primary keys to tables. - are usually numeric, they are often automatically generated by the DBMS, and they are free of semantic content (they have no special meaning).

Primary Key

- used to ensure that each row in a table is uniquely identifiable - used to uniquely identify each entity instance.

Characteristics of a Relational Table

-2 dimensional (has rows and columns) -row = 1 occurance -column = attribute (distinct name within that table) -intersection = a data value -all values in a column must conform to the same data format -each column has a specific range of values known as the attribute domain (size, datatype, range) -the order of the rows and columns does not matter -Each row has an attribute (or attributes) that is unique (for that table); a Primary Key

Types of Keys

-Composite -Super -Candidate -Primary -Foreign

Steps of Building an ERD

-Create a detailed narrative or the orgs description of operations -Identify the business rules -Identify the main entities and relationships -Develop the initial ERD -Identify the attributes and PKs that adequately describe the entities -Revise and review the ERD -Once you have discovered the relevant entities you can define the initial set of relationships among them and describe the attributes

Data Management Key Points:

-Data constitutes the building blocks of information. -Information is produced by processing data. -Information is used to reveal the meaning of data. -Accurate, relevant, and timely information is the key to good decision making. -Good decision making is the key to organizational survival in a global environment.

Normalization Levels

-First Normal Form (1NF) -Second Normal Form (2NF) -Third Normal Form (3NF) (Most databases should be 3NF in order to avoid the database anomalies.)

Concurrency control

-Purpose: to ensure that one user's work does not inappropriately influence anther user's work. - No concurrency control technique or mechanism is ideal for all circumstances, all involve trade-offs.

five components of a database system environment

1. Hardware 2. Software 3. People 4. Procedures 5. Data

Negatives of Databases

1. Increased Costs 2. Management Complexity 3. Maintaining Currency 4. Vendor Dependence 5. Frequent upgrading/replacement

4 complex database technologies

1. Very Large Databases 2. Big Databases 3. In memory Databases 4. Cloud Databases

Information

1. ____________________ is the result of processing raw data to reveal its meaning

The relational data model was developed in the ____.

1970s

The object-oriented data model was developed in the ____.

1980s

If one department chair—a professor—can chair only one department and one department can have only one department chair, then the entities PROFESSOR and DEPARTMENT exhibit a(n) ____________________ relationship.

1:1

Preferred relationship in a relational database is

1:M

The _________ relationship is the relational database norm.

1:M

A table that has all key attributes defined, has no repeating groups, and all its attributes are dependent on the primary key, is said to be in__.

1NF

A table with a composite key, has all key attributes defined, has no repeating groups, and all its attributes are dependent on at least part of the primary key, is said to be in ____.

1NF

From a structural point of view, 2NF is better than ____.

1NF

A table is in ___ if it is in 1NF and it includes no partial dependencies.

2NF

A table that is in 1NF and includes no partial dependencies is said to be in ____.

2NF

Before converting a table into 3NF, it is imperative the table already be in ____.

2NF

A table in 2NF and contains no transitive dependencies is in __.

3NF

A table that is in 2NF and contains no transitive dependencies is said to be in ____.

3NF

For most business transaction databases, we should normalize relations into __.

3NF

For most business transactional databases, we should normalize relations into ____.

3NF

Most designers consider the BCNF as a special case of the ____.

3NF

A table that has all key attributes defined, has no repeating groups, and all its attributes are dependent on the primary key, is said to be in ____.

4NF

A table where all attributes are dependent on the primary key and are independent of each other, and no row contains two or more multivalued facts about an entity, is said to be in ____.

4NF

Some very specialized applications may require normalization beyond the ____.

4NF?

Ad hoc query

A "spur-of-the-moment" question.

entity cluster

A "virtual" entity type used to represent multiple entities and relationships in the ERD. An entity cluster is formed by combining multiple interrelated entities into a single abstract entity object.

entity cluster

A "virtual" entity type used to represent multiple entities and relationships in the ERD. An entity cluster is formed by combining multiple interrelated entities into a single abstract entity object. An entity cluster is considered "virtual" or "abstract" in the sense that it is not actually an entity in the final ERD.

data dictionary

A DBMS component that stores metadata—data about data. The ____________________ contains data definitions as well as data characteristics and relationships. May also include data that is external to the DBMS.

Which of the following is an example of structured data?

A Spreadsheet

weak

A ____ entity has a primary key that is partially or totally derived from the parent entity in the relationship.

person's age

A ____ should be a derived attribute.

Field

A character or group of characters (alphabetic or numeric) that has a specific meaning. A field is used to define and store data.

Procedure

A collection of procedural and SQL statements that are assigned a unique name within the schema and stored in the database

File

A collection of related records. For example, a ______ might contain data about the students currently enrolled at Gigantic University.

index

A common practice is to create a(n) ____________________ on any field that is used as a search key, in comparison operations in a conditional expression, or when you want to list rows in a specific order.

Data quality

A comprehensive approach to ensuring the accuracy, validity, and timeliness of data.

transitive dependency

A condition in which an attribute is dependent on another attribute that is not part of the primary key.

full functional dependence

A condition in which an attribute is functionally dependent on a composite key but not on any subset of the key.

data independence

A condition in which data access is unaffected by changes in the physical data storage characteristics.

completeness constraint

A constraint that specifies whether each entity supertype occurence must also be a member of at least one subtype.

completeness constraint

A constraint that specifies whether each entity supertype occurrence must also be a member of at least one subtype. The completeness constraint can be partial or total. Partial completeness means that not every supertype occurrence is a member of a subtype; that is, there may be some supertype occurrences that are not members of any subtype. Total completeness means that every supertype occurrence must be a member of at least one subtype.

data anomaly

A data abnormality in which inconsistent changes have been made to a database. For example, an employee moves, but the address change is not corrected in all files in the database.

structural dependence

A data characteristic in which a change in the database schema affects data access, thus requiring changes in all access programs.

structural independence

A data characteristic in which changes in the database schema do not affect data access.

data dependence

A data condition in which data representation and manipulation are dependent on the physical data storage characteristics.

User-defined data type

A data type that a user can define by making it a subclass of a standard type or creating a type that behaves as an object.UDTs may also have defined functions and methods

Operational database

A database designed primarily to support a company's day-to-day operations. Also known as a transactional database, OLTP database, or production database.

Analytical database

A database focused primarily on storing historical data and business metrics used for tactical or strategic decision making. Such analysis typically requires extensive "data massaging" (data manipulation) to produce information on which to base pricing decisions, sales forecasts, market strategies, and so on.

Centralized database

A database located at a single site.

Extensible Markup Language(XML) database

A database system that stores and manages semistructured XML data.

General-purpose database

A database that contains a wide variety of data used in multiple disciplines.

Discipline-specific database

A database that contains data focused on specific subject areas.

Cloud database

A database that is created and maintained using cloud services, such as Microsoft Azure or Amazon AWS.

Multiuser database

A database that supports multiple concurrent users.

Single-user database

A database that supports only one user at a time.

Why is a table whose primary key consists of a single attribute automatically in 2NF when it is in 1NF?

A dependency based on only a part of a composite primary key is called a partial dependency. Therefore, if the PK is a single attribute, there can be no partial dependencies.

partial dependency

A dependency based on only a part of a composite primary key is called a(n) ____________________.

True

A dependency based on only a part of a composite primary key is known as a partial dependency.

False

A dependency of one nonprime attribute on another nonprime attribute is a partial dependency.

system catalog

A detailed system data dictionary that describes all objects in a database.

False

A determinant is any attribute whose value determines other values within a column.

dependency diagram

A diagram that depicts all dependencies found within a given table structure is known as a(n) ____________________.

False

A disadvantage of the relational database management system (RDBMS) is its inability to hide the complexities of the relational model from the user.

Data management

A discipline that focuses on the proper generation, storage, and retrieval of data.

Transaction

A discrete unit of work that must be completely processed or not processed at all

specialization hierarchy

A hierarchy that is based on the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype. Specialization is based on grouping unique characteristics and relationships of the subtypes.

Outer Join

A join in which rows that do not have matching values in common columns are nevertheless included in the result table

Equi-Join

A join in which the joining condition is based on equality between values in the common columns.Common values appear (redundantly) in the result table

inner join

A join operation in which only rows that meet a given criterion are selected. The join criterion can be an equality condition (natural join or equijoin) or an inequality condition (theta join). The inner join is the most commonly used type of join. Contrast with outer join.

Natural Join

A join that is the same as an equi-join except that one of the duplicate columns is eliminated in the result table

prime attribute

A key attribute, that is, an attribute that is part of a key or is the whole key. See also key attribute.

prime attribute

A key attribute; that is, an attribute that is part of a key or is the whole key. See also key attributes.

secondary key

A key used strictly for data retrieval purposes. For example, customers are not likely to know their customer number (primary key), but the combination of last name, first name, middle initial, and telephone number will probably match the appropriate table row. See also key.

Record

A logically connected set of one or more fields that describes a person, place, or thing. For example, the fields that constitute a __________ for a customer might consist of the customer's name, address, phone number, date of birth, credit limit, and unpaid balance.

distributed database

A logically related database that is stored in two or more physically independent sites.

candidate key

A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a superkey. See key.

composite key

A multiple-attribute key.

Workgroup database

A multiuser database that usually supports fewer than 50 users or is used for a specific department in an organization.

Trigger

A named set of SQL statements that are considered (triggered) when a data modification (i.e insert, update, delete ) or if certain data definitions are encountered. If a condition stated within a trigger is met, then a prescribed action is taken.

NoSQL

A new generation of database management systems that is not based on the traditional relational database model. Designed to handle the unprecedented volume of data, variety of data types and structures, and velocity of data operations that are characteristic of these new business requirements.

Query language

A nonprocedural language that is used by a DBMS to manipulate its data. An example of a query language is SQL.

True

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

set theory

A part of mathematical science that deals with sets, or groups of things, and is used as the basis for data manipulation in the relational model.

A potential problem with the design is that it may have

A performance problem

Database administrator (DBA)

A person or group responsible for establishing policies and procedures to control and protect a database. They work within guidelines set by data administration to control the database structure, manage data changes, and maintain DBMS programs

single-valued

A person's social security number would be an example of a(n) ____________________ attribute.

Structured Query Language(SQL)

A powerful and flexible relational database language composed of commands that enable users to create database and table structures, perform various types of data manipulation and data administration, and query the database to extract useful information.

iterative process

A process based on repetition of steps and procedures.

denormalization

A process by which a table is changed from a higher level normal form to a lower level normal form. Usually done to increase processing speed. Potentially yields data anomalies.

denormalization

A process by which a table is changed from a higher-level normal form to a lower-level normal form, usually to increase processing speed. Denormalization potentially yields data anomalies.

normalization

A process that assigns attributes to entities in such a way that data redundancies are reduced or eliminated.

normalization

A process that assigns attributes to entities so that data redundancies are reduced or eliminated.

existence-independent

A property of an entity that can exist apart from one or more related entities. Such a table must be created first when referencing an existence-dependent table.

existence-dependent

A property of an entity whose existence depends on one or more other entities. In such an environment, the existence-independent table must be created and loaded first because the existence-dependent key cannot reference a table that does not yet exist.

closure

A property of relational operators that permits the use of relational algebra operators on existing tables (relations) to produce new relations.

atomicity

A property of transactions that states that all parts of a transaction must be treated as a single logical unit of work in which all operations must be completed (committed) to produce a consistent database.

cardinality

A property that assigns a specific value to connectivity and expresses the range of allowed entity occurrences associated with am single occurrence of the related entity.

query

A question or task asked by an end user of a database in the form of SQL code. A specific request for data manipulation issued by the end user or the application to the DBMS.

natural key (natural identifier)

A real-world, generally accepted identifier used to identify real-world objects. As its name implies, a natural key is familiar to end users and forms part of their day-to-day business vocabulary.

Join

A relational operation that causes two tables with a common domain to be combined into a single table or view

repeating

A relational table must not contain ____________________ groups.

recursive relationship

A relationship found within a single entity type. For example, an EMPLOYEE is married to an EMPLOYEE or a PART is a component of another PART.

mandatory participation

A relationship in which one entity occurrence must have a corresponding occurrence in another entity. For example, an EMPLOYEE works in a DIVISION. (A person cannot be an employee without being assigned to a company's division.)

identifying relationship

A relationship in which related entities are existence-dependent. Also called a strong relationship or strong identifying relationship because the dependent entity's primary key contains the primary key of the parent entity.

non-identifying relationship

A relationship in which the primary key of the dependent (many side) entity does not contain the primary key of the related parent entity. Also known as a weak relationship.

weak relationship

A relationship in which the primary key of the related entity does not contain a primary key component of the parent entity. Also known as a non-identifying relationship.

What is a relationship, and what three types of relationships exist?

A relationship is an association among (two or more) entities. Three types of relationships exist: one-to-one (1:1), one-to-many (1:M), and many-to-many (M:N or M:M.)

strong (identifying) relationship

A relationship that occurs when two entities are existence-dependent; from a database design perspective, this relationship exists whenever the primary key of the related entity contains the primary key of the parent entity.

dependency diagram

A representation of all data dependencies (primary key, partial, or transitive) within a table.

Business Intelligence

A set of tools and processes used to capture, collect, integrate, store, and analyze data to support business decision making.

Online analytical processing(OLAP)

A set of tools that provide advanced data analysis for retrieving, processing, and modeling data from the data warehouse.

Desktop database

A single-user database that runs on a personal computer.

Boyce-Codd normal form (BCNF)

A special form of third normal form (3NF) in which every determinant is a candidate key. A table that is in BCNF must be in 3NF. See also determinant.

Boyce-Codd normal form (BCNF)

A special type of third normal form (3NF) in which every determinant is a candidate key. A table in BCNF must be in 3NF. See also determinant.

Data warehouse

A specialized database that stores historical and aggregated data in a format optimized for decision support.

Boolean

A specialty field in mathematics, known as ____________________ algebra, is dedicated to the use of logical devices.

Function

A stored subroutine that returns one value and has only input parameters

surrogate key

A system-assigned primary key, generally numeric and auto-incremented.

DROP

A table can be deleted from the database by using the ____________________ command.

third normal form (3NF)

A table is in 3NF when it is in 2NF and no nonkey attribute is functionally dependent on another nonkey attribute; that is, it cannot include transitive dependencies.

True

A table is in BCNF if every determinant in the table is a candidate key.

fourth normal form (4NF)

A table that is in 3NF and contains no multiple independent sets of multivalued dependencies.

hub

A warehouse of data packets housed in a central location on a local area network. It contains multiple ports that copy the data in the data packets to make it accessible to selected or all segments of the network.

existence

A weak entity must be ____________________-dependent.

associative

A(n) ____ entity is composed of the primary keys of each of the entities to be connected.

application

A(n) _____ might be written by a programmer or it might be created through a DBMS utility program

derived

A(n) ____________________ attribute need not be physically stored within the database.

wildcard

A(n) ____________________ character is a symbol that can be used as a general substitute for other characters or commands.

repeating group

A(n) ____________________ derives its name from the fact that a group of multiple entries of the same type can exist for any single key attribute occurrence.

Data Anomaly

A(n) ____________________ develops when all required changes in the redundant data are not made successfully

Data Warehouse

A(n) ____________________ focuses primarily on storing data used to generate information required to make tactical or strategic decisions.

Segment

A(n) ____________________ in a hierarchical model is the equivalent of a record in a file system.

Unique

A(n) ____________________ index is an index in which the index key can have only one pointer value (row) associated with it.

Business Rule

A(n) ____________________ is a brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization.

DBMS(Database Management System)

A(n) ____________________ is a collection of programs that manages the database structure and controls access to the data stored in the database.

Class

A(n) ____________________ is a collection of similar objects with a shared structure and behavior.

schema

A(n) ____________________ is a group of database objects, such as tables and indexes, that are related to each other.

Data Model

A(n) ____________________ is a relatively simple representation of more complex real-world data structures

Relational Diagram

A(n) ____________________ is a representation of the relational database's entities, the attributes within those entities and the relationships between those entities.

query

A(n) ____________________ is a specific request issued to the DBMS for data manipulation.

Index

A(n) ____________________ is an orderly arrangement used to logically access rows in a table.

join

A(n) ____________________ is performed when data is retrieved from more than one table at a time.

Domain

A(n) ____________________ is the attribute's set of possible values.

Candidate

A(n) ____________________ key can be described as a superkey without unnecessary attributes.

Equijoin

A(n) ____________________ links tables on the basis of an equality condition that compares specified columns of each table.

cascading

A(n) ____________________ order sequence can be created easily by listing several attributes, separated by commas, after the ORDER BY clause.

Data Dictionary

A(n) ____________________ provides a detailed description of all tables found within the user/designer-created database.

binary

A(n) ____________________ relationship exists when two entities are associated.

Strong

A(n) ____________________ relationship is also known as an identifying relationship.

subquery

A(n) ____________________, also known as a nested query or an inner query, is a query that is embedded (or nested) inside another query.

An entity cluster is considered "virtual" or "_____" in the sense that it is not actually an entity in the final ERD.

Abstract

attribute names

According to the data modeling checklist, ____________________ should be unique within the entity.

good decision making

Accurate, relevant, and timely information is the key to _______.

Performance tuning

Activities that make a database perform more efficiently in terms of storage and access speed.

Performance tuning

Activities that make the database perform more efficiently

Transaction begins in server; request is recorded on hard disk drive, transaction copied into actual database, checkpoint file is updated

Airline example

Referential Integrity

All foreign keys must be valid; either null or a value in the PK of another related table

True

All relational tables satisfy the 1NF requirements.

first normal form

All relational tables satisfy the ____________________ requirements.

binary relationship

An ER term for an association (relationship) between two entities. For example, PROFESSOR teaches COURSE.

participants

An ER term for entities that participate in a relationship. For example, in the relationship "PROFESSOR teaches CLASS," the teaches relationship is based on the participants PROFESSOR and CLASS.

ternary relationship

An ER term used to describe an association (relationship) between three entities. For example, a CONTRIBUTOR contributes money to a FUND from which a RECIPIENT receives money.

unary relationship

An ER term used to describe an association within an entity. For example, a COURSE might be a prerequisite to another COURSE.

recursive

An alias is especially useful when a table must be joined to itself in ____________________ queries.

Cannot be further subdivided.

An atomic attribute ____.

foreign key (FK)

An attribute or attributes in one table whose values must match the primary key in another table or whose values must be null. See key.

superkey

An attribute or attributes that uniquely identify each entity in a table. See key.

multi-valued

An attribute representing one or more college degrees belonging to a person would be a(n) ____________________ attribute.

composite attribute

An attribute that can be further subdivided to yield additional attributes. For example, a phone number such as 615-898-2368 may be divided into an area code (615), an exchange number (898), and a four-digit code (2368). Compare to simple attribute.

multivalued attributes

An attribute that can have many values for a single entity occurrence. For example, an EMP_DEGREE attribute might store the string "BBA, MBA, PHD" to indicate three different degrees held.

single-valued attribute

An attribute that can have only one value.

atomicity

An attribute that cannot be further divided is said to display ____________________.

atomic attribute

An attribute that cannot be further subdivided to produce meaningful components. For example, a person's last name attribute cannot be meaningfully subdivided into other name components; therefore, the last name attribute is ...

atomic attribute

An attribute that cannot be further subdivided to produce meaningful components. For example, a person's last name attribute cannot be meaningfully subdivided.

derived attribute

An attribute that does not physically exist within the entity and is derived via an algorithm. For example, the Age attribute might be derived by subtracting the birth date from the current date.

nonkey attribute

An attribute that is not part of a key.

nonprime attribute

An attribute that is not part of a key.

dependent

An attribute whose value is determined by another attribute.

abstract

An entity cluster is considered "virtual" or "____________________" in the sense that it is not actually an entity in the final ERD.

composite entity

An entity designed to transform an M:N relationship into two 1:M relationships. The composite entity's primary key comprises at least the primary keys of the entities that it connects. Also known as a bridge entity. See also linking table.

key

An entity identifier based on the concept of functional dependence; keys may be classified in several ways. See also superkey, candidate key, primary key (PK), secondary key, and foreign key.

____ is a generic entity type that is related to one or more entity subtypes.

An entity supertype

weak entity

An entity that displays existence dependence and inherits the primary key of its parent entity. For example, a DEPENDENT requires the existence of an EMPLOYEE.

False

An implementation-ready data model needn't necessarily contain enforceable rules to guarantee the integrity of the data.

True

An implementation-ready data model should contain a description of the data structure that will store the end-user data.

unique index

An index in which the index key can have only one associated pointer value (row).

Entity

An object of interest to the end user. Corresponds to a table in the relational environment. Represented by a rectangle and name is usually a noun

Database System

An organization of components that defines and regulates the collection, storage, management, and use of data in a database environment. Composed of the five major parts: hardware, software, people, procedures, and data.

strong

Another word for existence-independent is ____.

determinant

Any attribute in a specific row whose value directly determines other values in that row. See also Boyce-Codd normal form (BCNF).

prime attribute

Any attribute that is at least part of a key is known as a(n) ____________________.

Key attribute

Any attribute that is part of a key

determinant

Any attribute whose value determines other values within a row is called a(n) ____________________.

Relationship

Association between entities. Usually defined as a verb. Operate in both directions

True

At the heart of all data systems are the collection, storage, aggregation, manipulation, dissemination, and management of data.

Each column in a relation represents a(n) ____.

Attribute

Dependent

Attribute A determines attribute B (that is, B is functionally ____________________ on A) if all of the rows in the table that agree in value for attribute A also agree in value for attribute B.

Composite Attribute

Attribute that can be further subdivided to yield additional attributes

Single-valued Attribute

Attribute that can only have a single value (not necessarily a simple attribute)

Simple Attribute

Attribute that cannot be subdivided

Derived Attributes

Attribute whose value is calculated (derived) from other attributes. Doesn't need to be physically stored within the database. Sometimes referred to as computed attributes. Decision to store derived attributes depends on processing requirements and the constraints placed on application

____ are characteristics of entities.

Attributes

Candidate

BCNF can be violated only if the table contains more than one ____ key.

primary

Because a partial dependency can exist only if a table's primary key is composed of several attributes, a table whose ____________________ key consists of only a single attribute must automatically be in 2NF if it is in 1NF.

____ relationships are most common.

Binary

_________ relationships are most common

Binary

Correctly determining the cardinality of a relationship by evaluating from

Both ends

What are the requirements that two relations must satisfy in order to be considered union-compatible?

Both must have the same number of attributes (columns) and corresponding attributes (columns) must have the same (or compatible) domains (data types).

Another name for a composite entity is a ____ entity.

Bridge

False

Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

what products are included in Product line 1?

CASE could be used in constructing a query that asks

10. The ____ attribute(s) make up the primary key in the table definition: CLASS (CRS_CODE, CLASS_SECTION, CLASS_TIME, CLASS_ROOM, PROF_NUM)

CRS_CODE and CLASS_SECTION

Composite attribute

Can be further subdivided to yield additional attributes

Not null

Can be placed on a column to ensure that every row has a value for that column

Multivalued Attribute

Can have many values. Should not be implemented into a RDBMS. Try to fix by creating a new entity composed of the original mulitvalued attribute's components; make a 1:M relationship to the original entity

A ____ key can be described as a superkey without unnecessary attributes, that is, a minimal superkey.

Candidate

PRODUCT yields all possible pairs of rows from two tables—also known as the ____________________ product.

Cartesian

False

Character data can contain any character or symbol intended for mathematical manipulation.

Field

Character that has specific meaning

Attribute

Characteristics of entities

A(n) ____ is a collection of similar objects with a shared structure and behavior.

Class

The relationship ___ is difficult to establish if you know only one side of the relationship.

Classification

Guaranteed Access

Codd's rule of ____________________ states that every value in a table is guaranteed to be accessible through a combination of table name, primary key value, and column name.

join column(s)

Columns that join two tables. The join columns generally share similar values.

identifying

Composite keys are useful as identifiers of weak entities, where the weak entity has a strong ____________________ relationship with the parent entity.

Only once

Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed ____________________ in the M:N relationship.

ERD represents the

Conceptual database as viewed by the end user

Business Rules

Connectivities and cardinalities are usually based on ____________________ rules.

Data

Consists of raw facts. The word raw indicates that the facts have not yet been processed to reveal their meaning.

Multi valued type of attribute cannot be

Created into a DBMS

Oracle

DATE() and SYSDATE are special functions that return today's date in MS Access and ____________________, respectively.

Implicit locks are placed by

DBMS

The ____ serve(s) as the intermediary between the user and the database.

DBMS

the __ serve(s) as the intermediary between the user and the database a. DBMS b. metadata c. end-user data d. programming language

DBMS

Of the following normal forms, ____ is mostly of theoretical interest.

DKNF

exists when the same data are stored unnecessarily at different places.

Data Redundancy

Structured

Data are the result of formatting to facilitate storage of info

A(n) ____________________ provides a detailed description of all tables found within the user/designer-created database.

Data dictionary

Relational System

Data from related tables are combined into one result table or view and then displayed or used as input to a form or report definition

____ exists when different versions of the same data appear in different places.

Data inconsistency

transactions

Data maintenance is defined in units of work called

Computerized file systems

Data processing specialist converted computer file structure from manual system

duplication

Data redundancies are caused by ____________________ of data on every row entry.

True

Data redundancy produces data anomalies.

Unstructured data

Data that exists in its original, raw state; that is, in the format in which it was collected.

Semistructured data

Data that has already been processed to some extent.

Structured data

Data that has been formatted to facilitate storage, use, and information generation.

Semistructured data

Data thats already been processed to some extent

____ databases reflect the ever-growing demand for greater scope and depth in the data on which decision support systems increasingly rely.

Data warehouse?

time-variant data

Data whose values are a function of time. For example, time-variant data can be seen at work when the history of all administrative appointments (date of appointment and date of termination) are tracked.

False

Database designers determine the data and information that yield the required understanding of the entire business.

diagram

Dependencies can be identified with the help of a dependency ____________________.

False

Dependencies that are based on only a part of a composite primary key are called transitive dependencies.

True

Dependency diagrams are very helpful in getting a bird's eye view of all the relationships among a table's attributes.

True

Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

Metadata

Describes the data characteristics and the set of relationships that links the data found within the database. For example, the _________________ component stores information such as the name of each data element, the type of values (numeric, dates, or text) stored on each data element, and whether the data element can be left empty.

Verb

Describes the relationship between entities

non-overlapping

Disjoint subtypes are also known as ____________________ subtypes.

A ____ database supports data distributed across several different sites.

Distributed

Noncorrelated subqueries

Do not depend on data from the outer query Execute once for the entire outer query

Optional attribute

Does not require a value, can be left empty

Attributes may share a ____.

Domain

The set of possible values for an attribute is a ____.

Domain

The ___ refers to a specific table row as an entity instance.

ER model

Attribute

Each column in a relation represents a(n) ____________________.

Tuple

Each row in a relation is called a(n) ____________________

True

Each table in a relational database must have a primary key.

A(n) ____ database is used by an organization and supports many users across many departments.

Enterprise

A relationship is an association between ____.

Entities

A(n) ____ represents a particular type of object in the real world.

Entity

Strong entity

Entity can exist apart from all of its related entities; existence dependent. Also called a regular entity

Primary Key (ENTITY INTEGRITY)

Entity integrity describes a condition in which all tuples (i.e., rows or records) within a table are uniquely identified by their primary key. The unique value requirement prohibits a null primary key value, because nulls are not unique. - ensures that each row is uniquely identified by the primary key.

Which model has the highest level of abstraction

Entity relationship

False

Even when a good database blueprint is available, an applications programmer's view of the data should match that of the manager and the end user.

Entity Integrity

Every row in a table has a unique identifier (PK) which has no null values

If an entity can exist apart from one or more related entities, it is said to be ____-independent.

Existence

Weak relationship

Exists if the primary key of the related entity does not contain a primary key component of the parent entity; also known as a non-identifying relationship

Unary Relationship

Exists when an association is maintained within a single entry

data inconsistency

Exists when different and conflicting versions of the same data appear in different places.

Data inconsistency

Exists when different versions of the same data appears in different places.

Strong Relationship

Exists when the primary key of the related entity contains a primary key component of the parent entity; also known as an identifying relationship. Must load the "1" side in the 1:M relationship first

Data redundancy

Exists when the same data is stored unnecessarily at different places.

Binary Relationship

Exists when two entities are associated. Most common type of relationships

FROM

Explicit Join...ON commands are included in the __ clause

Cardinality

Expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity. Established by business rules.

Persistent Stored Modules (SQL/PSM)

Extensions defined in SQL:1999 that include the capability to create and drop modules of code stored in the database schema across user sessions

The ____ model is the end users' view of the data environment.

External

1. As rare as 1:1 relationships should be, certain conditions absolutely require their use.

1. Data and information are essentially the same thing.

10. A table is in BCNF if every determinant in the table is a foreign key.

10. Composite attributes make it easier to facilitate detailed queries.

10. In an SQL-based relational database, each table is dependent on every other table.

10. One disadvantage of the DBMS is that it increases the risk of data security breaches.

11. Relationships between entities always operate in one direction.

12. A disadvantage of the relational database management system (RDBMS) is its inability to hide the complexities of the relational model from the user.

14. In implementation terms, an entity is existence-dependent if it has a mandatory primary key.

14. The SELECT operator yields a vertical subset of a table.

15. A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

15. Field refers to a collection of related records.

16. Data anomaly is defined as the condition in which all of the data in the database are consistent with the real-world events and conditions.

16. In a natural join, the column on which the join was made occurs twice in the new table.

17. Dependencies that are based on only a part of a composite primary key are called transitive dependencies.

17. Structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data.

18. An advantage of database systems is that you needn't perform frequent updates and apply latest patches.

18. Referential integrity and participation are both bidirectional, meaning that they must be addressed in both directions along a relationship.

18. The external model is the representation of the database as "seen" by the DBMS.

19. The onetomany (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.

2. An implementation-ready data model needn't necessarily contain enforceable rules to guarantee the integrity of the data.

2. Normalization produces a lower normal form.

2. The Crow's Foot notation is less implementationoriented than the Chen notation.

20. Converting a database format from 1NF to 2NF is a complex process.

20. The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity.

22. The process of database design is a sequential process.

24. A determinant is any attribute whose value determines other values within a column.

26. Data stored at their highest level of granularity are said to be atomic data.

27. Atomic attributes are attributes that can be further subdivided.

3. Data is the result of processing raw facts to reveal its meaning.

3. Normalization is a process that is used for changing attributes to entities.

3. The order of the rows and columns is important to the DBMS.

30. The combination of normalization and ER modeling yields a useful ERD, whose entities can be translated into appropriate relationship structures.

31. A good relational DBMS excels at managing denormalized relations.

33. Normalization purity is often easy to sustain in the modern database environment.

35. Attributes should clearly define participation, connectivity, and document cardinality.

4. Character data can contain any character or symbol intended for mathematical manipulation.

4. When data are entered into a form and saved, they are placed in the underlying database as knowledge.

5. Even when a good database blueprint is available, an applications programmer's view of the data should match that of the manager and the end user.

5. The row's range of permissible values is known as its domain.

7. Database designers determine the data and information that yield the required understanding of the entire business.

7. Reporting anomalies in a table can cause a multitude of problems for managers and can be fixed through application programming.

7. Software vendors have adopted the Chen representation because of its compact representation.

7. The idea of determination is unique to the database environment.

8. Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

8. Database programming languages receive all application requests and translate them into the complex operations required to fulfill those requests.

8. Only a single attribute, not multiple attributes, can define functional dependence.

9. The Crow's Foot notation easily identifies multivalued attributes.

Participation

Failure to understand the distinction between mandatory and optional ____________________ in relationships might yield designs in which awkward (and unnecessary) temporary rows (entity instances) must be created just to accommodate the creation of required entities.

A dependency of one nonprime attribute on another nonprime attribute is partial dependency

False

A determinant is any attribute whose value determines other values within a column.

False

A foreign key must exist in both tables that have a relationship

False

A foreign key must exist in both tables that have a relationship.

False

A good relational DBMS excels at managing denormalized relations.

False

A manager and a programmer usually have the same view of the same data.

False

A query language is a procedural language.

False

A table is in BCNF if every determinant in the table is a foreign key.

False

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

False

All RDBMSs enforce integrity rules automatically.

False

All simple attributes are also single-valued.

False

All simple attributes are single valued

False

An ERM is dependent on the database type.

False

An operational database is sometimes referred to as an enterprise database.

False

Atomic attributes are attributes that can be further divided

False

Atomic attributes are attributes that can be further subdivided.

False

Attributes are types of entities.

False

Attributes cannot share a domain.

False

Attributes do not have a domain

False

Attributes do not have a domain.

False

Attributes have a domain that specifies the data type of the attribute.

False

Attributes should clearly define participation, connectivity, and document cardinality.

False

Because the relational model uses attribute values to establish relationships among tables, many database users correctly assume that the term relation refers to such relationships

False

Because the relational model uses attribute values to establish relationships among tables, many database users correctly assume that the term relation refers to such relationships.

False

Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

False

Character data can contain any character or symbol intended for mathematical manipulation

False

Character data can contain any character or symbol intended for mathematical manipulation.

False

Converting a database format from 1NF to 2NF is a complex process.

False

Corporations use only structured data.

False

Data and information are the same thing

False

Data modeling starts with a very complex representation, and as knowledge of the problem is gained, the model is simplified.

False

Data that display data inconsistency are referred to as lacking data cohesion.

False

Database designers determine the data and information that yield the required understanding of the entire business.

False

Database programming languages receive all application requests and translate them into the complex operations required to fulfill those requests.

False

Denormalization is a process for assigning attributes to entities.

False

Dependencies that are based on only a part of a composite primary key are called transitive dependencies

False

Dependencies that are based on only a part of a composite primary key are called transitive dependencies.

False

Derived attributes are stored in a special database table.

False

Disjoint subtypes are subtypes that contain nonunique subsets of the supertype entity set.

False

Eat model is depended on the database tupe

False

End-user interfaces require the end user to manually generate SQL code.

False

Entity subtypes do not inherit the relationships in which the supertype entity participates

False

Entity subtypes do not inherit the relationships in which the supertype entity participates.

False

Generalization is based on grouping unique characteristics and relationships of the subtypes.

False

Ideally, a primary key is composed of several attributes.

False

If a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF

False

Implementing non-overlapping subtypes requires the use of one discriminator attribute for each subtype

False

Implementing non-overlapping subtypes requires the use of one discriminator attribute for each subtype.

False

In Chen notation, entities and relationships must be oriented horizontally.

False

In Chen notation, there is no way to represent cardinality.

False

In a natural join, the column on which the join was made occurs twice in the new table

False

In a natural join, the column on which the join was made occurs twice in the new table.

False

In a page-level lock, the DBMS will lock an entire diskpage; also known as a "table level lock".

False

In a relational model, if A determines B, C, and D, you write A = B, C, D

False

In a relational model, if A determines B, C, and D, you write A = B, C, D.

False

In an ER diagram, primary keys are usually bolded.

False

In an SQL-based relational database, each table is dependent on another.

False

In specialization hierarchies with multiple levels of supertype/subtypes, a lower-level supertype inherits all of the attributes and relationships from all of its upper-level subtypes.

False

Many-to-many relationships are easily represented using a hierarchical model.

False

Normalization is a process that is used for changing attributes to entities.

False

Normalization is a very important database design ingredient and the highest level is always the most desirable.

False

Normalization produces a lower normal form.

False

Normalization purity is easy to sustain in the modern database environment.

False

One advantage of a database system over previous data management approaches is that the database system is considerably less complex.

False

Only a single attribute can define functional dependence

False

Only a single attribute, not multiple attributes, can define functional dependence

False

Only a single attribute, not multiple attributes, can define functional dependence.

False

Overlapping subtypes are subtypes that contain a unique subset of the supertype entity set.

False

Referential and entity integrity are two names for the same thing

False

Referential and entity integrity are two names for the same thing.

False

Relationships operate in one direction

False

Relationships operate only in one direction.

False

Repeating groups must be eliminated by making sure that each column defines a single entity.

False

Software vendors have adopted the Chen representation because of its compact representation.

False

The Crow's Foot model is less implementation-oriented than the Chen model.

False

The DBMS can easily handle multivalued attributes.

False

The DBMS reveals much of the database's internal complexity to the application programs and users.

False

The SELECT operator yields a vertical subset of a table

False

The SELECT operator yields a vertical subset of a table.

False

The combination of normalization and ER modeling yields a useful ERD, whose entities may now be translated into appropriate relationship structures.

False

The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity.

False

The hierarchical model is software-independent.

False

The idea of determination is unique to the database environment

False

The idea of determination is unique to the database environment.

False

The number of users determines whether the DBMS is classified as single-system or multiuser.

False

The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key

False

The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.

False

The order of the rows and columns is important to the DBMS.

False

The property of subtype discriminator enables an entity supertype to inherit the attributes and relationships of the subtype

False

The property of subtype discriminator enables an entity supertype to inherit the attributes and relationships of the subtype.

False

The relational model is hardware-dependent and software-independent.

False

The relationships depicted within the specialization hierarchy are sometimes described in terms of is-a relationships

False

There is never a good reason to use null values in a database.

False

To model time-variant data, you must create a new entity in a M:N relationship with the original entity.

False

True or False The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.

False

True or False. Only a single attribute, not multiple attributes, can define functional dependence.

False

True or false The order of the rows and columns is important to the DBMS.

False

Within a specialization hierarchy, a supertype can exist only within the context of a subtype.

False

Within an specialization hierarchy, a supertype can exist only within the context of a subtype.

False

Information implies familiarity, awareness, and understanding knowledge as it applies to an environment.

False KNOWLEDGE implies familiarity, awareness and understanding of INFORMATION as it applies to an environment.

Structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data.

False Structural INDEPENDENCE exists when you can change the file structure without affecting the application's ability to access the data.

One disadvantage of the DBMS is that it increases the risk of data security breaches.

False The DBMS DECREASES the security risk.

Data and information are essentially the same thing.

False. Data is raw fact. Information is processed data.

Create a detailed narrative of the organizations description of operations

First step of building an ERD

Placeholder

Flag

3NF

For most business transactional databases, we should normalize relations into ____.

____ keys work with primary keys to properly implement relationships in the relational model.

Foreign

Many-to-Many

Fortunately, the problems inherent in the ____________________ relationship can easily be avoided by creating a composite entity.

GROUP BY

Frequency distributions can be created quickly and easily using the SQL ____________________ clause.

time-variant data

From a data modeling point of view, ____________________ refer to data whose values change over time and for which you must keep a history of the data changes.

Derived

From a strictly database point of view, ____ attribute values can be calculated when they are needed to write reports or invoices.

The attribute B is ____ the attribute A if each value in column A determines one and only one value in column B.

Functionally dependent on

____ is the bottom-up process of identifying a higher-level, more generic entity supertype from lower-level entity subtypes.

Generalization

Data models

Graphical system capturing nature and relationship of data

Embedded SQL

Hard-coded sql statements included in a program written in another language, such as C or Java.

RBDMS

Hierarchical structure where it's at the top and records are at the bottom

The SQL command that lets you insert rows into a table is ____.

INSERT

___ yields only the rows that appear in both tables.

INTERSECT

Composite keys are useful as identifiers of weak entities, where the weak entity has a strong_____ relationship with the parent entity.

Identifying

relationships

Identifying the attributes of the entities helps you better understand the ____________________ among entities.

recu

If an employee within an EMPLOYEE entity has a relationship with itself, that relationship is known as a ____ relationship.

RDBMS

If database tables are treated as though they were files in a file system, the ___________________ never has a chance to demonstrate its superior data-handling capabilities.

1:1

Natural identifier

If one exists, a data modeler uses a ____ as the primary key of the entity being modeled.

True

If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key , the attribute (B) is fully functionally dependent on (A).

Existence-dependent

If the entity can exist in the database only when it is associated with another related entity occurrence; has a mandatory foreign key (foreign key attribute cannot be null)

Referential integrity

If the foreign key contains a value, that value refers to an existing valid row in another relation

Referential

If the foreign key contains either matching values or nulls, the table that makes use of that foreign key is said to exhibit ____________________ integrity

null

If you add a new column to a table that already has rows, the existing rows will default to a value of ____________________ for the new column.

unique index

If you use a surrogate key, you must ensure that the candidate key of the entity in question performs properly through the use of "____________________" and "not null" constraints.

SMALLINT

If your integer values are relatively small, use ____________________ instead of INT.

DBMS provides these advantages:

Improved data sharing. Improved data security. Better data integration. Minimized data inconsistency. Improved data access. Improved decision making. Increased end-user productivity.

Natural

In A ____ key is a real-world, generally accepted identifier used to uniquely identify real- world objects.

Small Circle

In Crow's Foot notation, an optional relationship between entities is shown by drawing a(n) ____________________ on the side of the optional entity.

optional participation

In ER modeling, a condition in which one entity occurrence does not require a corresponding entity occurrence in a particular relationship.

composite identifier

In ER modeling, a key composed of more than one attribute.

optional attribute

In ER modeling, an attribute that does not require a value; therefore, it can be left empty.

required attribute

In ER modeling, an attribute that must have a value. In other words, it cannot be left empty.

Correlated subquery

In SQL, a subquery in which processing the inner query depends on data from the outer query

Conditional

In SQL, all ____________________ expressions evaluate to true or false.

null

In SQL, the absence of an attribute value. Note that a null is not a blank.

fourth normal form

In ____________________ no row may contain two or more multivalued facts about an entity.

Crows Foot Notation

In ____________________, a three-pronged symbol represents the "many" side of the relationship.

Chen Notation

In ____________________, relationships are represented by a diamond connected to the related entities through a relationship line.

one

In a 1:M relationship, you must always create the table for the ____________________ side first.

partial completeness

In a generalization hierarchy, means that not every supertype occurrence is a member of a subtype; that is, there may be some supertype occurrences that are not members of any subtype.

total completeness

In a generalization/specialization hierarchy, a condition in which every supertype occurrence must be a member of at least one subtype.

entity supertype

In a generalization/specialization hierarchy, a generic entity type that contains the common characteristics of entity subtypes.

entity subtype

In a generalization/specialization hierarchy, a subset of an entity supertype.

entity supertype

In a generalization/specialization hierarchy, refers to a generic entity type that contains the common characteristics of entity subtypes.

entity subtype

In a generalization/specialization hierarchy, refers to a subset of an entity supertype where the entity supertype contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.

surrogate

In a real-world environment, changing granularity requirements might dictate changes in primary key selection, and those changes might ultimately require the use of ____________________ keys.

repeating group

In a relation, a characteristic describing a group of multiple entries of the same type for a single key attribute occurrence. For example, a car can have multiple colors for its top, interior, bottom, trim, and so on.

repeating group

In a relation, a characteristic describing a group of multiple entries of the same type that exist for a single key attribute occurrence. For example, a car can have multiple colors (top, interior, bottom, trim, and so on).

Data integrity

In a relational database, a condition in which the data in the database complies with all entity and referential integrity constraints.

Attribute

In a relational table, each column has a specific range of values known as the ____________________ domain.

overlapping subtype

In a specialization hierarchy, describes a condition where each entity instance (row) of the supertype can appear in more than one subtype.

disjoint subtype (non-overlapping subtype)

In a specialization hierarchy, refers to a unique and non-overlapping subtype entity set.

identifiers

In an ERM, unique names of each entity instance. In the relational model, such identifiers are mapped to primary keys in tables.

True

In an SQL-based relational database, rows in different tables are related based on common values in common attributes

domain

In data modeling, the construct used to organize and describe an attribute's set of possible values.

Data Processing

In early computer file systems, the ____________________ created computer file structures, wrote the software that managed the data within the structures, and designed application programs that produced reports based on the file data.

partial dependency

In normalization, a condition in which an attribute is dependent on only a portion (subset) of the primary key.

Method

In object-oriented terms, a(n) ____________________ defines an object's behavior.

(min, max)

In the ERD, cardinality is indicated using the ____ notation.

query

In the SQL environment, the word ____________________ covers both questions and actions.

True

In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.

availability

In the context of data security, it refers to the accessibility of data whenever required by authorized users and for authorized purposes.

True

In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data.

inheritance

In the object-oriented data model, the ability of an object to inherit the data structure and methods of the classes above it in the class hierarchy. See also class hierarchy.

islands of information

In the old file system environment, pools of independent, often duplicated, and inconsistent data created and managed by different departments.

Attributes

In the original ERM described by Chen, relationships do not contain ____________________.

Keys

In the relational model, ____________________ are important because they are used to ensure that each row in a table is uniquely identifiable.

tuple

In the relational model, a table row.

linking table

In the relational model, a table that implements an M:M relationship. See also composite entity.

primary key (PK)

In the relational model, an identifier composed of one or more attributes that uniquely identifies a row. Also, a candidate key selected as a unique entity identifier. See also key.

existence-dependent

In the relationship "EMPLOYEE claims DEPENDENT" the DEPENDENT entity is ____________________ on the EMPLOYEE entity.

SELECT

Include each attribute after the ____ keyword

API provides data structure

Independence

Relationship Degree

Indicates the number of entities or participants associated with a relationship

_____ is the result of processing raw data to reveal its meaning.

Information

derived

Instead of storing a person's age, it is better to store the date of birth and use the difference between that value and the system date as a(n) ____________________ attribute.

Data warehousing - >100, TB-PB

Integrated decision support system derived from various operational databases

____ yields only the rows that appear in both tables.

Intersect

Information

Is used to reveal the meaning of data

True

It is possible for a table in 2NF to exhibit transitive dependency, where the primary key may rely on one or more nonprime attributes to functionally determine other nonprime attributes.

A(n) ____ process is based on repetition of processes and procedures

Iterative

According to naming conventions described in Chapter 2, ____ would be the best name for a column representing the charges per hour in a table named JOB.

JOB_CHG_HOUR

____ is the body of information and facts about a specific subject.

Knowledge

Record

Logically connected set of fields that describes person place thing

Relational database model enables you to view data

Logically instead of physically

The relational database model enables you to view data ____ rather than ____.

Logically, physically

In a relational database, you cannot implement

M:M

Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed only once in the ____ relationship.

M:N

True

M:N relationships are not appropriate in a relational model.

Correlated subqueries

Make use of data from the outer query Execute once for each row of the outer query Can use the EXISTS operator

Processing Speed

Mean minimal access time which may be achieved by minimizing the number and complexity of logically desirable relationships. High processing speeds are often a top priority in a database design. Forced to include derived attributes in the design

Weak Entities

Meets two conditions. Entity is existence dependent and the entity has a primary key that is partially or totally derived from the parent entity in the relationship. Strong (identifying) relationship indicates that the related entity is weak.

____ provide(s) a description of the data characteristics and the set of relationships that link the data found within the database.

Metadata

Binary relationships

Most common

semistructured

Most data that can be encountered are best classified as _____ .

____ attributes can have many values.

Multivalued

Required attribute

Must have a value, cannot be left empty

Costs and Risks of Database Approach

New, specialized personnel Installation and management cost andcomplexity Conversion costs Need for explicit backup and recovery Organizational conflict

ON or WHERE

No matter what form of join you are using, there should be __ or ___ specification

When data is stored in many spreadsheets

No sync, nulls, and redundancies occur

False

Normalization is a process that is used for changing attributes to entities.

False

Normalization is a very important database design ingredient, and the highest level is always the most desirable.

False

Normalization produces a lower normal form.

Entities

Normalization represents a micro view of the ____ within the ERD.

normal

Normalization works through a series of stages called ___________________ forms.

True

Normalization works through a series of stages called normal forms.

A derived attribute

Not stored within the database

Entities

Noun form describing a person, place, event, or concept

In an outer join, the matched pairs would be retained and any unmatched values in the other table would be left ____.

Null

Relational databases minimize

Null entries and duplicate entries

design trap

Occurs when a relationship is improperly or incompletely identified and, therefore, is represented in a way that is not consistent with the real world. The most common design trap is known as a fan trap.

False

One advantage of a database system over previous data management approaches is that the database system is considerably less complex.

An entity identifier is composed of

One attribute

False

One disadvantage of the DBMS is that it increases the risk of data security breaches.

Optional Participation

One entity occurrence does not require a corresponding entity occurrence in a particular relationship. Minimum cardinality is 0 for the optional entity (Optionality)

Mandatory Participation

One entity occurrence requires a corresponding entity occurrence in a particular relationship

Recursive relationship

One in which a relationship can exist between occurrences of the same entity set

Identifiers

One or more attributes that uniquely identify each entity instance (ex: primary key)

____ is a set of tools that work together to provide an advanced data analysis environment for retrieving, processing, and modeling data from the data warehouse.

Online analytical processing

False

Only a single attribute, not multiple attributes, can define functional dependence.

Logical data

Only has true false values

Within a specialization hierarchy, every subtype can have ____ supertype(s) to which it is directly related.

Only one

Participation is ____ if one entity occurrence does not require a corresponding entity occurrence in a particular relationship

Optional

The term "____" is used to label any condition in which one or more optional relationships exist.

Optionality

RDBMS Vendors

Oracle, ibm, Microsoft SQL, MySQL

Subtypes that contain nonunique subsets of the supertype entity set are known as ____ subtypes.

Overlapping

Cartesian

PRODUCT yields all possible pairs of rows from two tables—also known as the ____________________ product.

In the following table description, ____ is the primary key. PRODUCT (PROD_CODE, PROD_DESCRIPT, PROD_PRICE, PROD_ON_HAND, VEND_CODE)

PROD_CODE

____ completeness means that not every supertype occurrence is a member of a subtype.

Partial

Optional

Participation is ____________________ if one entity occurrence does not require a corresponding entity occurrence in a particular relationship.

A ____ should be a derived attribute.

Person's age

Entity

Person, place, thing; Represents a particular object in the real world; nouns

The preferred placement for a foreign key when working with a 1:1 relationship is ____.

Place a foreign key in one of the entities

____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false.

Predicate

The most important characteristic of an entity is its ____ key, used to uniquely identify each entity instance.

Primary

Composite Identifier

Primary key composed of more than one attribute

Iterative Process

Process based on repetition of processes and procedures. Database design is iterative

Advantages of the Database Approach

Program-data independence Planned data redundancy Improved data consistency Improved data sharing increased application development productivity Enforcement of standards Improved data quality Improved data accessibility and responsiveness Reduced program maintenance Improved decision support

warehousing

Proper data ____________________ design requires carefully defined and controlled data redundancies to function properly.

Qualifications such as <ANY or >= ALL instead of ___ are also useful

A(n) _____ is a specific request issued to the DBMS for data manipulation.

Query

The response of the dbms to a query is

Query result set

If database tables are treated as though they were files in a file system, the _____________________________________________ never has a chance to demonstrate its superior data-handling capabilities.

RDBMS (relational database management system)

True

RDBMSs enforce integrity rules automatically.

Data can temporarily be moved from

Ram to hard disk drive

1:1 relationship should be

Rare in any relational database design

Formatted

Raw data must be properly ____________________ for storage, processing and presentation.

formatted

Raw data must be properly ____________________ for storage, processing and presentation.

True

Raw data must be properly formatted for storage, processing and presentation.

End user data is

Raw facts of interest to the end user

____ relationships occur when there are multiple relationship paths between related entities.

Redundant

Foreign Key (REFERENTIAL INTEGRITY)

Referential integrity describes a condition in which a foreign key value has a match in the corresponding table, or in which the foreign key value may be null (depending upon the business rules). - means that, if the foreign key contains a value, that value refers to an existing valid tuple (row) in another relation.

EER diagram (EERD)

Refers to the entity-relationship diagram resulting from the application of extended entity relationship concepts that provide additional semantic content in the ER model.

granularity

Refers to the level of detail represented by the values stored in a table's row. Data stored at their lowest level of granularity are said to be atomic data.

True

Relational models view data as part of a table or collection of tables in which all key values must be identified.

Verb associating two nouns in a business rule

Relationship in a data model

Participation

Relationship strength depends on how the primary key of the related entity is formulated, while the relationship ____________________ depends on how the business rule is written.

True

Repeating groups must be eliminated by ensuring that each row defines a single entity.

False

Reporting anomalies in a table can cause a multitude of problems for managers and can be fixed through application programming.

ERD

Represents the conceptual database as viewed by the end user, depicts the databases main components - entities, attributes and relationships

The SQL command that lets you select attributes from rows in one or more tables is ____.

SELECT

____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.

SELECT

To list all the contents of the PRODUCT table, you would use ____.

SELECT * FROM PRODUCT;

Mobile apps use

SQL NoSQL and Hadoop; HTML5 and JavaScript

COMMIT

SQL command that PERMANENTLY saves data changes to database

ROLLBACK

SQL command that restores the database table content to its last condition, to the condition that existed after the last commit statement

The ______ is the conceptual organization of the entire database as viewed by the database administrator

Schema

index key

See index.

nonkey attribute

See nonprime attribute.

Database should capture the maximum possible

Semantics/meaning

Most data you encounter is

Semi structured

A ____ attribute is one that cannot be subdivided.

Simple

True

Since a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF.

Desktop database

Single user database

extended entity relationship model (EERM)

Sometimes referred to as the enhanced entity relationship model; the result of adding more semantic constructs (entity supertypes, entity subtypes, and entity clustering) to the original entity relationship (ER) model.

unique

Specialization is based on grouping ____________________ characteristics and relationships of the subtypes.

Databases

Specialized structures that allow computer-based systems to store, manage, and retrieve data very quickly.

Dynamic SQL

Specific SQL code generated on the fly while an application is processing

Another word for existence-independent is ____.

Strong

Spreadsheet

Structured data

natural

Surrogate primary keys are especially helpful when there is no ____ key.

1. The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.

1. The process of database design is a sequential process.

10. A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

11. A dependency based on only a part of a composite primary key is known as a partial dependency.

11. Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

11. In an SQL-based relational database, rows in different tables are related based on common values in common attributes

12. A data warehouse can store data derived from many sources.

12. A table is in fourth normal form if it is in third normal form and has no independent multivalued dependencies.

12. Connectivities and cardinalities are established by concise statements known as business rules.

12. RDBMSs enforce integrity rules automatically.

13. Relational algebra defines the theoretical way of manipulating table contents using relational operators.

13. Relational models view data as part of a table or collection of tables in which all key values must be identified.

13. The same data might be simultaneously structured and unstructured depending on the intended processing.

14. The objective of normalization is to ensure that each table conforms to the concept of well-formed relations.

15. M:N relationships are not appropriate in a relational model.

15. Repeating groups must be eliminated by ensuring that each row defines a single entity.

15. The DIFFERENCE operator subtracts one table from the other.

16. Dependency diagrams are very helpful in getting a bird'seye view of all the relationships among a table's attributes.

16. In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side must be loaded first.

16. Today, most relational database products can be classified as object/relational.

17. The DIVIDE operation uses one singlecolumn table (e.g., column "a") as the divisor and one twocolumn table (e.g., columns "a" and "b") as the dividend.

17. The network model has structural level dependence.

17. Unary relationships are common in manufacturing industries.

18. A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures.

18. All relational tables satisfy the 1NF requirements.

19. A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.

19. In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data.

19. One disadvantage of a database system over previous data management approaches is increased costs.

2. Data processing can be as simple as organizing data to reveal patterns.

2. You can think of a table as a persistent representation of a logical relation.

20. As rare as 1:1 relationships should be, certain conditions absolutely require their use.

21. Since a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF.

21. To implement a small database, a database designer must know the "1" and the "M" sides of each relationship and whether the relationships are mandatory or optional.

22. A table is in 2NF if it is in 1NF, and it includes no partial dependencies.

23. It is possible for a table in 2NF to exhibit transitive dependency, where the primary key may rely on one or more nonprime attributes to functionally determine other nonprime attributes.

28. Normalization should be part of the design process.

29. Normalization represents a micro view of the entities within the ERD.

3. An entity in the entity relationship model corresponds to a table in the relational environment.

3. An implementation-ready data model should contain a description of the data structure that will store the end-user data.

32. The advantage of higher processing speed must be carefully weighed against the disadvantage of data anomalies.

34. Unnormalized database tables often lead to various data redundancy disasters in production databases.

4. In order to meet performance requirements, portions of the database design may need to be occasionally denormalized.

4. In the entity relationship model, a table row corresponds to an entity instance.

4. Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.

5. Data constitute the building blocks of information.

5. Denormalization produces a lower normal form.

5. In the Chen and Crow's Foot notations, an entity is represented with a rectangle containing the entity's name.

6. Each table in a relational database must have a primary key.

6. In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.

6. In the original Chen notation, each attribute is represented by an oval with the attribute name connected to an entity rectangle with a line.

6. Metadata describe the data characteristics and the set of relationships that links the data found within the database

7. The only way to access the data in a database is through the DBMS.

8. A composite identifier is a primary key composed of more than one attribute.

8. Data redundancy produces data anomalies.

9. A table is in BCNF if every determinant in the table is a candidate key.

9. If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).

Because a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF

A(n) ____ is perceived as a two-dimensional structure composed of rows and columns.

Table

unique values

The "____" characteristic of a primary key states that: The PK must uniquely identify each entity instance. A primary key must be able to guarantee unique values. It cannot contain nulls.

security-compliant

The "____" characteristic of a primary key states that: The selected primary key must not be composed of any attribute(s) that might be considered a security risk or violation. For example, using a Social Security number as a PK in an EMPLOYEE table is not a good idea.

Conceptual

The Chen model is specially useful to illustrate some of the ____________________ elements of database design.

Implementation

The Crow's Foot model is more ____________________-oriented than the Chen model.

Solid

The Crow's Foot notation depicts the strong relationship with a(n) ____________________ line between the entities.

(1:1)

The Crow's foot symbol with two parallel lines indicates ____ cardinality.

Qualifier

The _____NOT, ANY, and ALL may be used in front of IN or with logical operators such as =,> and <

System

The ____________________ catalog can be described as a detailed system data dictionary that describes all objects within the database, including data about table names, the table's creator and creation date, the number of columns in each table, the data type corresponding to each column, index filenames, index creators, authorized users, and access privileges.

Completeness

The ____________________ constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.

Subschema

The ____________________ defines the portion of the database "seen" by the application programs that produce information from the data.

Schema

The ____________________ is the conceptual organization of the entire database as viewed by the database administrator.

extended entity relationship model

The ____________________ is the result of adding more semantic constructs to the original entity relationship (ER) model.

ERD

The ____________________ provides the big picture, or macro view, of an organization's data requirements and operations.

ER model ERM

The ____________________ refers to a specific table row as an entity instance.

1:M

The ____________________ relationship is the relational database norm.

HAVING

The _____________________ clause of the GROUP BY statement operates very much like the WHERE clause in the SELECT statement.

subtype discriminator

The attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

key attribute

The attributes that form a primary key.

key attributes

The attributes that form a primary key. See also prime attribute.

100

The basic SQL vocabulary has a fewer than ____________________ words.

connectivity

The classification of the relationship between entities. Classifications include 1:1, 1:M, and M:N.

query result set

The collection of data rows returned by a query.

DBMS (Database Management Systems)

The collection of programs that manages the database structure and controls access to the data stored in the database.

Normalization

The combination of ____________________ and ER modeling yields a useful ERD, whose entities may now be translated into appropriate table structures.

True

The common columns in joined tables are usually the primary key of the dominant table and the foreign key of the dependent table in 1:M relationships.

compromises that include denormalization

The conflicts between design efficiency, information requirements, and processing speed are often resolved through ____.

Design Standards

The database design must conform to design standards that minimize data redundancies, avoid nulls, govern the presentation of all components within the database design, and allow you to work with well defined components and evaluate the interaction of those components

Making sure all business rules are identified is

The database designers job

Second Normal Form (2NF)

The database is in first normal form, all nonkey attributes in the table must be functionally dependent on the entire primary key.

collection of files

The database structure in a DBMS is stored as a ______.

Structured Query Language (SQL)

The de facto query language and data access standard supported by the majority of DBMS vendors

The _____ is the result of adding more semantic constructs to the original entity relationship (ER) model. The enhanced entity relationship mode

The enhanced entity relationship mode or EERM

EER diagram (EERD)

The entity relationship diagram resulting from the application of extended entity relationship concepts that provide additional semantic content in the ER model.

mandatory

The existence of a(n) ____ relationship indicates that the minimum cardinality is at least 1 for the mandatory entity.

First Normal Form (1NF)

The fields contain only atomic values and no repeating groups to try to avoid this.

first normal form (1NF)

The first stage in the normalization process. It describes a relation depicted in tabular format, with no repeating groups and a primary key identified. All nonkey attributes in the relation are dependent on the primary key.

first normal form (1NF)

The first stage in the normalization process. It describes a relation depicted in tabular format, with no repeating groups and with a primary key identified. All nonkey attributes in the relation are dependent on the primary key.

Entity

The following example exhibits ____________________ integrity: The CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. Similarly, the AGENT table's primary key is AGENT_CODE, and this primary key column also is free of null entries.

False

The idea of determination is unique to the database environment.

Composite

The index key can have multiple attributes, this is called a(n) ____________________ index.

Relation

The logical view of the relational database is facilitated by the creation of data relationships based on a logical construct known as a(n) ____________________.

consistent

The main concern with redundant relationships is that they remain ____________________ across the model.

The mandatory relationship indicates

The minimum cardinality is at least 1

fan trap

The most common design trap is known as a(n) ____________________.

Primary

The most important characteristic of an entity is its ____ key, used to uniquely identify each entity instance.

Numeric.

The most likely data type for a surrogate key is ____.

True

The network model has structural level dependence.

relationship degree

The number of entities or participants associated with a relationship. A relationship degree can be unary, binary, ternary, or higher.

Cartesian Join

The number of rows is equal to the number of rows in each table, multiplied together

True

The objective of normalization is to ensure that each table conforms to the concept of well-formed relations.

False

The only way to access the data in a database is through the DBMS.

True

The only way to access the data in a database is through the DBMS.

False

The order of the rows and columns is important to the DBMS.

relational schema

The organization of a relational database as described by the database administrator.

its expected use

The organization of data within folders in a manual file system is determined by _____.

Enterprise database

The overall company data representation, which provides support for present and expected future needs.

Data processing (DP) specialist

The person responsible for developing and managing a computerized file processing system.

true, false, dont know

The predicate form is based on three-logic value ____ but allows for more complex operations

place a foreign key in one of the entities

The preferred placement for a foreign key when working with a 1:1 relationship is to ____.

redundancy

The price paid for increased performance through denormalization is a larger amount of ___________________.

entity

The primary key's main function is to uniquely identify a(n) ____ within a table.

anomalies

The problem with transitive dependencies is that they still yield data ____________________.

Database design

The process that yields the description of the database structure and determines the database components. The second phase of the Database Life Cycle.

ANSI defines for events that signal the end of a transaction. Which is a ROLLBACK?

The program is abnormally terminated

Foreign

The proper use of ____________________ keys is crucial to controlling data redundancy.

entity integrity

The property of a relational table that guarantees each entity has a unique value in a primary key and that the key has no null values.

Information requirements

The quest for timely information may be the focus of the database design. Complex info requirements may dictate data transformations and may expand the number of entities and attributes within the design. Database may have to sacrifice some of its clean design structures and/or high transaction speed to ensure maximum info generation

Closure

The relational operators have the property of ____________________; that is, the use of relational algebra operators on existing tables (relations) produces new relations.

When the PK of one entity contains the PK of another

The relationship is strong

Information

The result of processing raw data to reveal its meaning.

determination

The role of a key. In the context of a database table, the statement "A determines B" indicates that knowing the value of attribute A means that the value of attribute B can be looked up.

False

The row's range of permissible values is known as its domain.

second normal form (2NF)

The second stage in the normalization process in which a relation is in 1NF and there are no partial dependencies (dependencies in only part of the primary key).

second normal form (2NF)

The second stage in the normalization process, in which a relation is in 1NF and there are no partial dependencies (dependencies in only part of the primary key).

Domain

The set of possible values for a given attribute

optionality

The term "____" is used to label any condition in which one or more optional relationships exist.

Logical Design

The term ____________________ is used to refer to the task of creating a conceptual data model that could be implemented in any DBMS.

Islands of Information

The term ____________________ refers to scattered locations storing the same basic data.

synonym

The use of different names to identify the same object, such as an entity, an attribute, or a relationship; synonyms should generally be avoided. See also homonym.

homonym

The use of the same name to label different attributes. Homonyms generally should be avoided. Some relational software automatically checks for homonyms and either alerts the user to their existence or automatically makes the appropriate adjustments. See also synonym.

value

The value-expression form requires a match to the ___ expression

physical data format

The way a computer "sees" (stores) data.

logical data format

The way a person views data within the context of a problem domain.

For most purposes in business database design, __ stages are as high as you need to go in the normalization process.

Three

If you have three different transitive dependencies, __ different determinants exist.

Three

____ data refer to data whose values change over time and for which you must keep a history of the data changes.

Time-variant

Flags

To avoid nulls, some designers use special codes, known as ____________________, to indicate the absence of some value.

DROP INDEX

To delete an index, use the ____________________ command.

outer join

To determine which customer did not place order, an _____ is used

context

To reveal meaning, information requires ___________.

Context

To reveal meaning, information requires ____________________.

True

Today, most relational database products can be classified as object/relational.

_____ completeness means that every supertype occurrence must be a member of at least one subtype.

Total

Fishbone diagram shows

Troubleshooting to find the problem

A composite identifier is a primary key composed of more than one attribute

True

A composite identifier is a primary key composed of more than one attribute.

True

A data dictionary contains metadata—data about data

True

A data dictionary contains metadata—data about data.

True

A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures

True

A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures.

True

A data model is usually graphical.

True

A data warehouse can store data derived from many sources.

True

A design trap occurs when a relationship is improperly or incompletely identified and is therefore represented in a way that is not consistent with the real world.

True

A design trap occurs when a relationship is improperly or incompletely identified and, therefore, is represented in a way that is not consistent with the real world.

True

A determinant is any attribute whose value determines other values within a row

True

A left outer join on tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table

True

A left outer join on tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table.

True

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind

True

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

True

A recursive relationship is one in which a relationship can exist between occurrences of the same entity set.

True

A relationship is identified by a name that describes the relationship.

True

A strong relationship exists if the primary key of the related entity contains at least one primary key of the parent entity

True

A table is a persistent representation of a logical relation

True

A table is in 2NF if it is in 1NF and it includes no partial dependencies.

True

A table is in BCNF if every determinant in the table is a candidate key.

True

A table is in fourth normal form if it is in third normal form and has no independent multivalued dependencies.

True

A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.

True

All attributes are either simple or composite.

True

All relational tables satisfy the 1NF requirements.

True

An entity cluster is a "virtual" entity type used to represent multiple entities and relationships in the ERD.

True

An entity supertype can have disjoint or overlapping entity subtypes.

True

An implementation-ready data model should contain a description of the data structure that will store the end-user data.

True

As rare as 1:1 relationships should be, certain conditions absolutely require their use

True

As rare as 1:1 relationships should be, certain conditions absolutely require their use.

True

At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship

True

At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship.

True

Atomicity does not indicate permanence

True

Atomicity requires that all portions of the transaction must be treated as a single, logical unit of work in which all operations are applied and completed to produce a consistent database.

True

Because a partial dependency can exist only if a table's primary key is composed of several attributes, if a table in 1NF has a single-attribute primary key, then the table is automatically in 2NF.

True

Business rules must be rendered in writing.

True

Cardinality expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity.

True

Certain conditions require 1:1 relationships

True

Connectivities and cardinalities are established by business rules.

True

Corporations use only structured data

True

Current relational database software generally provides only a system catalog (and not a data dictionary)

True

Current relational database software generally provides only a system catalog (and not a data dictionary).

True

DBMSs use indexes for many different purposes

True

DBMSs use indexes for many different purposes.

True

Data constitute the building blocks of info

True

Data constitute the building blocks of information.

True

Data constitutes the building blocks of information.

True

Data dictionary contains metadata- data about data

True

Data model is usually graphical

True

Data processing can be as simple as organizing data to reveal patterna

True

Data processing can be as simple as organizing data to reveal patterns.

True

Denormalization produces a lower normal form

True

Denormalization produces a lower normal form.

True

Dependency diagrams are helpful in getting a birds-eye view of all the relationships among a tables attributes

True

Dependency diagrams are very helpful in getting a bird's-eye view of all the relationships among a table's attributes.

True

Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used

True

Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

True

ER diagram represents the conceptual database as viewed by the end user

True

Each row in the relational table is known as an entity instance or entity occurrence in the ER model.

True

Each table in a relational database must have a primary key

True

Each table in a relational database must have a primary key.

True

Entity supertypes and subtypes are organized in a specialization hierarchy.

True

Hard disk is 200 times slower than RAM

True

Historically, a manual file system was composed of a system of file folders and filing cabinets.

True

If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A)

True

If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).

True

In an SQL-based relational database, rows in different tables are related based on common values in common attributes.

True

In both the Chen and Crow's Foot models, an entity is represented with a rectangle containing the entity's name.

True

In order to meet performance requirements, you may have to denormalize portions of the database design.

True

In the Chen model, a multivalued attribute is connected to the owning entity with a double line.

True

In the original Chen model, each attribute is represented using an oval with the attribute name connected to the entity with a line.

True

Initially the files within a computer file system were similar to manual files.

True

It is possible for a table in 2NF to exhibit transitive dependency

True

It is possible for a table in 2NF to exhibit transitive dependency, where one or more attributes may be functionally dependent on non-key attributes

True

It is possible for a table in 2NF to exhibit transitive dependency, where the primary key may rely on one or more nonprime attributes to functionally determine other nonprime attributes.

True

M:N relationships are not appropriate in a relational model.

True

Manual file system was a filing cabinet

True

Metadata present a more complete picture of the data in the database than the data itself.

True

Most real-world database transactions are formed by more than one database request

True

Normalization represents a micro view of the entities within the ERD.

True

Normalization should be part of the design process.

True

Normalization works through a series of stages called normal forms

True

Normalization works through a series of stages called normal forms.

True

Nulls can create problems when count, average, and sum is used

True

Numeric data are data on which you can perform meaningful arithmetic procedures

True

Numeric data are data on which you can perform meaningful arithmetic procedures.

True

One disadvantage of a database system over previous data management approaches is increased costs.

True

One important inheritance characteristic is that all entity subtypes inherit their primary key attribute from their supertype.

True

One of the disadvantages of the network model was the lack of structural independence.

True

RDBMSs enforce integrity rules automatically

True

RDBMSs enforce integrity rules automatically.

True

Relational models view the data as part of a table or collection of tables in which all key values must be identified

True

Relational models view the data as part of a table or collection of tables in which all key values must be identified.

True

Repeating groups must be eliminated by making sure that each row defines a single entity.

True

Some designs use redundant relationships as a way to simplify the design.

True

Specialization is the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype.

True

Structural dependence occurs when access to the file is dependent on its structure.

True

Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION

True

Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION.

True

Tables within a database share common attributes that enable the tables to be linked together

True

Tables within a database share common attributes that enable the tables to be linked together.

True

The DBMS cannot guarantee that the semantic meaning of a transaction truly represents the real-world event.

True

The DBMS cannot handle multi valued attributes

True

The DIFFERENCE operator subtracts one table from the other

True

The DIFFERENCE operator subtracts one table from the other.

True

The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend

True

The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend.

True

The ER diagram represents the conceptual database as viewed by the end user.

True

The ER model refers to a specific table row as an entity instance.

True

The ER model refers to a specific table row as an entity occurrence.

True

The advantage of higher processing speed must be carefully weighed against the disadvantage of data anomalies

True

The advantage of higher processing speed must be carefully weighed against the disadvantage of data anomalies.

True

The completeness constraint can be partial or total.

True

The difference operator subtracts one table from the other

True

The entity relationship model is limited to conceptual modeling, with no implementation component.

True

The entity supertype contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.

True

The network model has structural level dependence.

True

The only way to access the data in a database is through the DBMS.

True

The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage

True

The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.

True

The relationships depicted within the specialization hierarchy are sometimes described in terms of "is-a" relationships.

True

The same data might be simultaneously structured and unstructured depending on the intended processing.

True

The terms data model and database model are often used interchangeably.

True

The word "entity" in the ER model corresponds to a table.

True

Today, most relational database products can be classified as object/relational.

True

True or False An implementation-ready data model should contain a description of the data structure that will store the end-user data.

True

True or False Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

True

True or False. Data processing can be as simple as organizing data to reveal patterns.

True

True or False. One disadvantage of a database system over previous data management approaches is increased costs.

True

True or False. RDBMSs enforce integrity rules automatically.

True

True or False. Tables must have the same attribute characteristics (the columns and domains must be compatible) to be used in a UNION

True

True or False. Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.

True

Unnormalized database tables often lead to various data redundancy disasters in production databases.

True

We are now said to be entering the "knowledge age."

True

With partial dependencies, data redundancies occur because every row entry requires duplication of data

True

With partial dependencies, data redundancies occur because every row entry requires duplication of data.

True

Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.

True

You can think of a table as a persistent representation of a logical relation

True

You can think of a table as a persistent representation of a logical relation.

True

You should always load data from the 1 side of a 1:M relationship.

True

union-compatible

Two or more tables that share the same column names and have columns with compatible data types or domains.

CHAR

U.S. state abbreviations are always two characters, so ____________________(2) is a logical choice for the data type representing a state column.

____ combines all rows from two tables, excluding duplicate rows.

UNION

The SQL command that modifies an attribute's values in one or more table's rows is ____.

UPDATE

A ____ relationship exists when an association is maintained within a single entity.

Unary

Primary keys may be indicated by

Underlining

Non-overlapping subtypes are subtypes that contain a(n) ____ subset of the supertype entity set. unique

Unique

If you use a surrogate key, you must ensure that the candidate key of the entity in question performs properly through the use of the "____" and "not null" constraints.

Unique index

____ data exist in the format in which they were collected.

Unstructured

A database is prone to

Update anomalies

Hierarchical model

Upside down tree; each child has only one parent

Homonym

Use of the same attribute name to label different attributes

Connectivity

Used to describe relationship classification

Associative (composite) entities

Used to implement M:N relationships between two or more entities. Composed of the PKs of each of the entities to be connected

External schema

User View Subsets of Conceptual Schema Can be determined from busniess-function entiy matrics DBA determines schema for different users.

Entity relationship

Uses connectivity to label relationship types

CREATE INDEX

Using the ____________________ command, SQL indexes can be created on the basis of any selected attribute.

Primary Key

Usually, a data modeler uses a natural identifier as the ____________________ of the entity being modeled, assuming that the entity has a natural identifier.

Proper data ____________________ design requires carefully defined and controlled data redundancies to function properly.

Warehousing

BCNF

When a nonkey attribute is the determinant of a key attribute the table is in 3NF but not ____________________.

make sure entities are in normal form before table structures are created.

When designing a database, you should ____. (Hint: It involves normalization, and what should be done prior to creating tables.)

weak

When the PK of one entity does not contain the PK of a related entity, the relationship is ____.

enterprise database

When the database is used by the entire organization and supports many users (more than 50, usually hun- dreds) across many departments

Logical

When you can change the internal model without affecting the conceptual model, you have ____________________ independence.

database creation

With the exception of the ____________________ process, most RDBMS vendors use SQL that deviates little from the ANSI standard SQL.

functional dependence

Within a relation R, an attribute B is functionally dependent on an attribute A if and only if a given value of attribute A determines exactly one value of attribute B. The relationship "B is dependent on A" is equivalent to "A determines B," and is written as AB.

True

Within the database environment, a data model represents data structures with the purpose of supporting a specific problem domain.

Inventory should only have 2, but it display 7 ! Wrong

Wrong

___________________________________ is a special language used to represent and manipulate data elements in a textual format.

XML

Oracle 11g is an example of a(n) ____.

XML/Hybrid data model

attribute names

You can indicate just the attributes that have required values by listing the ____________________ inside parentheses after the table name.

True

You can think of a table as a persistent representation of a logical relation.

time-variant

____ data refer to data whose values change over time and for which you must keep a history of the data changes.

Data warehouse

____ databases reflect the ever-growing demand for greater scope and depth in the data on which decision support systems increasingly rely.

foreign

____ keys work with primary keys to properly implement relationships in the relational model.

joining

____________________ a large number of tables takes additional input/output (I/O) operations and processing logic, thereby reducing system speed.

Attributes

____________________ are characteristics of entities.

Primary Keys

____________________ are underlined in an ER diagram.

Composite

____________________ attributes can be subdivided.

partial

____________________ completeness means some supertype occurrences that are not members of any subtype.

total

____________________ completeness means that every supertype occurrence must be a member of at least one subtype.

Data Inconsistency

____________________ exists when different and conflicting versions of the same data appear in different places.

Data Independence

____________________ exists when it is possible to make changes in the data storage characteristics without affecting the application program's ability to access the data.

Data Redundancy

____________________ exists when the same data are stored unnecessarily at different places.

Data Management

____________________ is a discipline that focuses on proper generation, storage and retrieval of data.

UML (Unified Modeling Language)

____________________ is a language based on OO concepts that describes a set of diagrams and symbols used to graphically model a system.

normalization

____________________ is a process to help reduce the likelihood of data anomalies

XML(Extensible Markup Language)

____________________ is a special language used to represent and manipulate data elements in a textual format.

Metadata

____________________ is data about data through which the end-user data are integrated and managed

JOIN

____________________ is the real power behind the relational database, allowing the use of independent tables linked by common attributes.

Outer

____________________ joins are especially useful when you are trying to determine what value(s) in related tables cause(s) referential integrity problems.

Granularity

____________________ refers to the level of detail represented by the values stored in a table's row.

M:N

____________________ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.

reserved

____________________ words are words used by SQL to perform specific functions.

SELECT

____________________, coupled with appropriate search conditions, is an incredibly powerful tool that enables you to transform data into information.

Partial completeness is symbolized by ____.

a circle over a single line

Data quality

a comprehensive approach to promoting the accuracy, validity, and timeliness of the data.

Deadlock or deadly embrace

a condition that can occur during concurrent processing in which each of two or more transactions is waiting to access data that the other transaction has locked.

User defined data types

a data type that a user can define by making it a subclass of a standard type or creating a type that behaves as an object. UDTS may also have defined functions and methods.

Replicated database is

a database in which portions of the database are copied to two or more computers.

Partitioned database is

a database in which portions of the database are distributed to two or more computers

Distributed database is

a database that is stored and processed on two or more computers.

Business rules are derived from ____.

a detailed description of an organization's operations

System Catalog

a detailed system data dictionary that describes all objects within the database including data about table names, the table's creator and creation date, the number of columns in each table, the data type corresponding to each column, index filenames, index creators, authorized users, and access privileges

Data management

a discipline that focuses on the proper generation, storage, and retrieval of data. Given the crucial role that data play.

Log is

a file that contains a record of database changes. The log contains before-images and after-images.

Database Administration (DBA)

a function that concerns the effective use and control of a particular database and its related application.

Entity supertype

a generic entity type that is related to one or more entity subtypes

specialization hierarchy

a hierarchy that is based on the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype. Specialization is based on grouping unique characteristics and relationships of the subtypes

Composite Key

a key that is made up of more than one attribute

Surrogate Key

a key we create to be a PK

Shared lock locks

a lock against a data resource in which only one transaction can update the data but many transactions can concurrently read those data.

Exclusive lock locks

a lock on a data resource that no other transaction can read or update

Optimistic locking

a locking strategy that assumes no conflict will occur, processes a transaction, and then checks to determine whether conflict did occur. If so, the transaction is aborted.

Pessimistic locking

a locking strategy that prevents conflict by placing locks before processing database read and write requests.

query language

a nonprocedural language—one that lets the user specify what must be done without having to specify how

surrogate key

a primary key created by the database designer to simplify the identification of entity instancs.

design trap

a problem that occurs when a relationship is improperly or incompletely identified and therefore is represented in a way that is not consistent with the real world.

Subquery

a query that is embedded(nested) inside another query - query nested in another query

Dirty Read is

a read of data that have been changed but not yet committed to a database. Such changes may later be rolled back and removed from the database. - Transaction 1 read a row changed by transaction 2 - Later transaction 2 cancels its change

natural key/identifier

a real world generally accepted identifier used to distinguish or uniquely identify real world objects

Natural Identifier

a real-world, generally accepted identifier used to identify real world objects. familiar to end users and forms part of their day-to-day vocabulary

After-image is

a record of a database entity after a change. Used in recovery to perform rollforward

Before-image is

a record of a database entity before a change. Used in recovery to perform rollback.

Dependency Diagram

a representation of all data dependencies (PK, Partial or Transitive) within a table - arrows on top are good dependencies - arrows on bottom are bad (partial & transitive)

Databases

a self-describing collection of related records, or, for relational databases, of related tables.

Transaction or Logical units of work (LUWs)

a series of actions to be taken on a database such that all of them are performed successfully or none of them are performed at all

An entity cluster is formed by combining multiple interrelated entities into ____.

a single abstract entity object

Nonrepeatable read is

a situation that occurs when a transaction reads data it has previously read and finds modifications or deletions caused by a committed transaction.

query

a specific request issued to the DBMS for data manipulation, predefined and routinely processed.

which of the following is an example of structured data? a. A Web page c. A memo b. An e-mail d. A spreadsheet

a spreadsheet

a subquery can also return a list of values if it includes the keyword

Associative Entity (bridge entity, composite entity, or linking table)

a table used to link the tables that were originally a M:M relationship

MIN

aggregate function that yields the minimum attribute value encountered in a given column

2NF

all the key attributes are defined (no repeating groups in the table) , all remaining attributes are dependent on the primary key, and it includes no partial dependencies

1NF

all the key attributes are defined (no repeating groups in the table) and when all remaining attributes are dependent on the primary key

Hardware

all the system's physical devices

Key Attribute

an attribute that is part of a key

Keys

an attribute(s) we use to "determine" other attribute values

Data Administration

an enterprise wide function that concerns the effective use and control of an organization's data assets. A person can perform it but more often it is performed by a group. Specific functions include setting data standards and policies and providing a forum for conflict resolution.

____ is a generic entity type that is related to one or more entity subtypes.

an entity supertype

The lost update problem or concurrent update problem

an error condition in which one user's data changes are overwritten by another user's data changes.

A table that displays data redundancies yields ____.

anomalies

Determinant

any attribute in a specific determines other values in that row.

Super Key

any attribute or combination of attributes that will uniquely identify every row in the table

Primary Key

any candidate key that we select to be an identifier

rollback work

ask sql to empty the log file

TERNARY relationship

association between THREE entities

BINARY relationship

association between TWO entities - most common relationship

UNARY relationship

association within an entity (course is a pre-rec to another course)

ACID transaction is one that is

atomic, consistent, isolated, and durable.- atomic: happens as whole- durable: changes are permanent

A(n) ____ is the equivalent of a field in a file system.

attribute

In a relational table, each column has a specific range of values known as the ____________________ domain.

attribute

Foreign Key

attribute or combination of attributes in one table whose values must match the primary key i another (parent) table or whose values must be null

Non-Prime Attribute

attribute that is not part of a key

In the original ERM described by Chen, relationships do not contain ____________________.

attributes

In the specialization hierarchy there is a ____ relationship between a subtype and supertype.

b. 1:1

accurate, relevant, and timely information is the key to __ a. data management b. good decision making c. knowledge d. understanding

b. good decision making

_______relationships are most common

binary

A(n) ____________________ is a brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization.

business rule

>=ALL

can be used to match with the maximum value in a set

BCNF can be violated only if the table contains more than one ____ key.

candidate

An atomic attribute ____.

cannot be further subdivided

An automatic attribute__.

cannot be further subdivided

Repository

centralized storehouse of metadata

Structural independence

change file structure without affecting data access

Repeating Groups

characteristic describing a group of multiple entities of the same type that exist for a single key attribute occurrence. - repeating group = multivalued attribute

LEFT OUTER JOIN

clause causes customer data to appear even if there is no corresponding order data

Inner Join

clause is an alternative to WHERE clause, and is used to match primary and foreign keys

where

clause of the select command is also used for multiple table operations

clause performs the equality check for common columns of the two tables

The relational operators have the property of ____________________; that is, the use of relational algebra operators on existing relations (tables) produces new relations.

closure

The database structure in a DBMS is stored as a ____.

collection of files

the database structure in a DBMS is stored as a __ a. file b. collection of files c. set of key/value pairs d. collection of queries

collection of files

Explicit locks are placed by

command

AUTOCOMMIT (ON/OFF)

command that specifies whether changes are made permanent after each data modification command or only when work is explicitly made permanent by the comit work command

transaction

complete set of closely related updated commands that must all done, or none of them done for the database to remain valid

The ____________________ constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.

completeness

A ____ attribute can be further subdivided to yield additional attributes.

composite

The associative entity is also known as a ____ entity.

composite

The conflicts between design efficiency and processing speed are often resolved through__

compromises that include denormalization

The conflicts between design efficiency, information requirements, and processing speed are often resolved through ____.

compromises that include renormalization

Case tools

computer-aided software engineering

Resource locking prevents

concurrent processing problems by disallowing sharing by locking data that are retrieved for update.

Transitive Dependency

condition where an attribute is dependent on another attribute that is not part of the primary key

A(n) ____ is a restriction placed on the data.

constraint

General-purpose databases

contain a wide variety of data used in multiple disciplines—for example, a census database that contains general demographic data

Discipline-specific databases

contain data focused on specific subject areas

____ are important because they help to ensure data integrity.

contraints

____ are normally expressed in the form of rules.

contraints

begin transaction

creates a log file and starts recording all changes (insertion, deletions and updates)

left outer join

customer_t was named first and this is the table we want the rows returned.

__ is used to reveal the meaning of data

d. information

A derived attribute is indicated in the Chen model by a ____

dashed line

Metadata

data about data, through which the end-user data are integrated and managed.

A(n) _______ develops when all required changes in the redundant data are not made successfully.

data anomaly

A(n) ____ enables a database administrator to define schema components.

data definition language (DDL)

A ____ contains at least all of the attribute names and characteristics for each table in the system.

data dictionary

Distributed database

data distributed across several sites

subquery

data from a ____ cannot be included in the final results

Information

data in context which is processed to reveal meaning. THE BEDROCK OF KNOWLEDGE

__ exists when different versions of the same data appear in different places a. Data inconsistency c. Better data integration b. Data consistency d. Improved decision making

data inconsistency

____________________ exists when different and conflicting versions of the same data appear in different places.

data inconstancy

____________________ exists when it is possible to make changes in the data storage characteristics without affecting the application program's ability to access the data.

data inpendence

Data redundancy produces __.

data integrity problems

Data redundancy produces ____.

data integrity problems

True

data is ubiquitous (abundant, global, everywhere) and pervasive (unescapable, prevalent, persistent)

Centralized database

data located at a single site

an_____ is a relatively simple representation of more complex real-world data structures.

data model

Information

data processed to increase knowledge in the person using the data

In early computer file systems, a(n) ___________________________________ was hired to create a computer-based system that would track data and produce required reports.

data processing specialist

Data independence

data storage characteristics do not affect data access

Metadata

data that describes the properties and context of user data.

Unstructured data

data that exist in their original (raw) state—that is, in the format in which they were collected

The ____ structure is quite different from that of an operational or transactional database.

data warehouse

the __ structure is quite different from that of an operational or transactional database a. data warehouse c. enterprise database b. workgroup database d. distributed database

data warehouse

time-variant data

data whose values are a function of time. For example, time variant data can be seen to work when the history of all administrative appointments(date of appointment and date of termination) are tracked. Implemented by creating a new entity with a 1:M relationship. Example manager and manager history

time-variant data

data whose values change over time and for which you must keep a history of the data changes. - requires a multivalued attribute which is resolved by creating a new table.

A(n) ___________________________________ is a collection of programs that manages the database structure and controls access to the data stored in the database.

database management system

the phrase __ refers to an organization of components that define and regulate the collection, storage, management and use of data within a database environment (a)database management system (c)management system (b)database management (d)database system

database system

In a __ diagram, the arrows above the attributes indicate all desirable dependencies.

dependency

specialization hierarchy

depicts the arrangement of higher-level entity supertypes (parent entities) and lower-level entity subtypes (child entities).

A(n) ____________________ attribute need not be physically stored within the database.

derived

From a strictly database point of view, ____ attribute values can be calculated when they are needed to write reports or invoices.

derived

business intelligence

describes a comprehensive approach to capture and process business data with the purpose of generating information to support business decision making.

CHEN

describes relationships (1:1, 1:M, and M;N) among entities at the conceptual level with the help of ER diagrams

Conceptual schema

designers and developers

maintenance and data integrity

designing a database so that data about about each object are kept in separate tables simplifies

A _________ is any attribute whose value determines other values within a column.

determinant

Attribute A __ attribute B if all of the rows in the table that agree in value for attribute A also agree in value for attribute B.

determines

a __ database supports data distributed across several different sites a. single-user c. centralized b. multiuser d. distributed

distributed

A(n) ____________________ is the attribute's set of possible values.

domain

OVERLAPPING subtypes

each entity instance of the supertype may appear in more than one subtype

TOTAL completeness

each instance of a super may appear in more than one subtype - overlapping subtype

UNION clause

each query must output the same number of columns to use the

inheritance

enables an entity subtype to inherit the attributes and relationships of the supertype.

The extended entity relationship model (EERM) is sometimes referred to as the ____.

enhanced entity relationship model

a(n) __ database is used by an organization and supports many users across many departments a. desktop c. enterprise b. workgroup d. transactional

enterprise

A relationship is an association between ____

entities

Normalization represents a micro view of the __ within the ERD.

entities

(n) ____ represents a particular type of object in the real world.

entity

A(n) ____ is anything about which data are to be collected and stored.

entity

The primary key's main function is to uniquely identify a(n) ____ within a table

entity instance or row

The ____ model was developed to allow designers to use a graphical tool to examine structures rather than describing them with text.

entity relationship

The ERM forms the basis of a(n) ____.

entity relationship diagram

The default comparison condition for the subtype discriminator attribute is the ____ comparison.

equality

CASE

establishing IF THEN ELSE logical processing within an sql statement can now be accomplished by using the ____ keyword

BCNF

every determinant in the table is a candidate key.

An entity is said to be ____-dependent if it can exist in the database only when it is associated with another related entity occurrence.

existence

In the relationship "EMPLOYEE claims DEPENDENT" the DEPENDENT entity is ____________________ on the EMPLOYEE entity.

existence-dependent

Partial Dependency

exists when an attribute is dependent on only a portion of the primary key.

The ____________________ is the result of adding more semantic constructs to the original entity relationship (ER) model

extended entity relationship model (EERM) extended entity relationship model

File system

extensive programming cannot perform ad hoc queries system administration is complex and difficult difficult to make changes to existing structures security features are likely to be inadequate

A foreign key must exist in both tables that have a relationship.

false

Atomic attributes are attributes that can be further divided.

false

Ideally, a primary key is composed of several attributes.

false

In specialization hierarchies with multiple levels of supertype/subtypes, a lower-level supertype inherits all of the attributes and relationships from all of its upper-level subtype.

false

Only a single attribute, not multiple attributes, can define functional dependence.

false

Relationships operate only in one direction.

false

Software vendors have adopted the Chen representation because of its compact representation

false

The Crow's Foot model is less implementation-oriented than the Chen model.

false

The existence of a mandatory relationship indicates that the minimum cardinality is 1 for the mandatory entity.

false

True or false A manager and a programmer usually have the same view of the same data.

false

True or false ... Business rules apply to businesses and government groups, but not to other types of organizations such as religious groups or research laboratories.

false

a query language is a procedural language

false

an operational database is sometimes referred to as an enterprise database

false

corporations use only structured data

false

data and information are essentially the same thing

false

database programming language receive all application requests and translate them into the complex operations required to fulfill those requests

false

implementating non-overlapping subtypes requires the use of one discriminator attribute for each subtype.

false

information implies familiarity, awareness, and understanding knowledge as it applies to an environment

false

one advantage of a database over previous data management approaches is that the database system is considerably less complex

false

one disadvantage of the DBMS is that it increases the risk of data security breaches

false

structural dependence exists when it is possible to make changes in the file structure without affecting the application program's ability to access the data

false

the DBMS reveals much of the database's internal complexity to the application programs and users

false

A ____ occurs when you have one entity in two 1:M relationships to other entities, thus producing an association among the other entities that is not expressed in the model.

fan trap

a __ is a character or group of characters that has a specific meaning (a)database (c)column (b)field (d)file

field

a __ is a collection of related records (a)database (c)column (b)field (d)file

file

To avoid nulls, some designers use special codes, known as ____________________, to indicate the absence of some value.

flags

In a real-world environment, we must strike a balance between design integrity and ____.

flexibility

analytical databases

focus primarily on storing historical data and business metrics used exclusively for tactical or strategic decision making

the proper use of ____________________ keys is crucial to controlling data redundancy.

foreign

Data must be properly _____ for storage, processing and presentation.

formatted

Raw data must be properly ____________________ for storage, processing and presentation.

formatted

Accurate, relevant, and timely information is the key to ____.

good decision making

____________________ refers to the level of detail represented by the values stored in a table's row.

granularity

Generalization

grouping of COMMON attributes into a SUPERtype entity

Specialization

grouping of UNIQUE attributes into a SUBtype entity

CASE

has four forms and can be constructed using the either an expression that equates to a value or predicate

In the ____ model, each parent can have many children, but each child has only one parent.

hierarchical

In the ____ model, the basic logical structure is represented as an upside-down tree.

hierarchical

One of the limitations of the ____ model is that there is a lack of standards.

hierarchical

physical data format

how the computer must work with the data

logical data format

how the human being views the data

Unstructured Data

images, video, documents

disjoint subtype

in a specialization hierarchy, a unique and nonoverlapping subtype entity set

full outer join

in this case all rows from both tables will be returned and matched, if possible including any rows that do not have a match in the other table

A(n) _________ is an orderly arrangement used to logically access rows in a table

index

The property of ____ enables an entity subtype to inherit the attributes and relationships of the supertype.

inheritance

the property of ____ enables an entity subtype to inherit the attributes and relationships of the supertype.

inheritance

Online analytical processing (OLAP)

is a set of tools that work together to provide an advanced data analysis environment for retrieving, processing, and modeling data from the data warehouse

Specialization

is a top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype. Example, identifying multiple entity subtypes from the original entity supertype

NATURAL

is an optional keyword

ad hoc query

is created to obtain information as the need arises

correlated subquery

is processed from the outside in

Generalization

is the bottom-up process of identifying a higher-level, more generic entity supertype from lower-level entity subtypes. Example, identifying a "string instrument" entity supertype from multiple instrument subtypes

distinct

is used when we do not care how many orders a customer has placed, as long as they have placed an order

Transaction is called atomic because

it it performed as a unit.

The organization of the data within the folders in a manual file system was determined by ____.

its expected use

the organization of the data within the folders in a manual file system was determined by __ a. the date of creation c.the title of the documents in the folder b.its expected used d.t he data processing specialist

its expected use

self join

joining a table with itself

same

joining and subqueries can sometimes produce the ___ results

Prime Attribute

key attribute that is part of a key or is the whole key. - prime attribute = if an attribute is part of the key

__ is the body of information and facts about a specific subject a. Data b. Information c. Knowledge d. A database

knowledge

correlated

like almost all other exists subqueries, is a _____ subquery

COUNT

lists total number of rows containing non-null values

When you can change the internal model without affecting the conceptual model, you have ____________________ independence.

logical

Codd's rule of ____ states: Application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns).

logical data independence

When designing a database, you should__.

make sure entities are in normal for before table structures are created

When designing a database, you should ____.

make sure entities are in normal form before table structures are created

UPDATE

makes changes to data tables

Data ____ is a discipline that focuses on proper generation, storage and retrieval of data.

management

Data ____________________ is a discipline that focuses on proper generation, storage and retrieval of data.

management

A specialization hierarchy can have ____ level(s) of supertype/subtype relationships.

many

Students and classes have a ____ relationship.

many-to-many

begin transaction and end transaction

mark the boundaries of a logical unit of work

subquery

may only include one attribute

__ provide(s) a description of the data characteristics and the set of relationships that link the data found within the database a. Queries b. End-user data c. Metadata d. Information

metadata

Candidate Key

minimal number of attributes to identify every row

Candidate Key

minimal super-key, that is, one that does not contain a subset of attributes that is itself a supe-key

When indicating cardinality, the first value represents the ___ number of associated entities.

minimum

A(n) ____'s main function is to help you understand the complexities of the real-world environment.

model

CASE

more common applications are :1) to make up for SQL lack of enumerated <data type> 2) to perform if then calculations 3) for translations 4) to avoid expectations

A workgroup database is a(n)____ database.

multiuser

a workgroup database is a(n) __ database a. single-user c. enterprise b. multiuser d. distributed

multiuser

performance

n order to meet ___________________ requirements, you may have to denormalize some relations.

A ____ key is a real-world, generally accepted identifier used to distinguish that is, uniquely identify-real-world objects.

natural

A ____ key is a real-world, generally accepted identifier used to uniquely identify real-world objects.

natural

Surrogate primary keys are especially helpful when there is no ____ key.

natural

If one exists (and there are no security issues), a data modeler may use a ____ as the primary key of the entity being modeled.

natural identifier

If one exists, a data modeler uses a ____ as the primary key of the entity being modeled.

natural identifier

from

natural join is an optional key word when the join is defined in the ____ clause

A derived attribute ____.

need not be physically stored within the database

In the ____ model, the user perceives the database as a collection of records in 1:M relationships, where each record can have more than one parent.

network

The "____" characteristic of a primary key states that: The PK should not have embedded semantic meaning. An attribute with embedded semantic meaning is probably better used as a descriptive characteristic of the entity rather than as an identifier.

nonintelligent

____________________ is a process to help reduce the likelihood of data anomalies.

normalization

1NF, 2NF, and 3NF are__.

normalization stages

The WHERE clause

normally cannot include aggregate functions, but because the aggregate is performed in the subquery its result can be used in the outer query's WHERE clause.

PARTIAL completeness

not every supertype occurrence is a member of a subtype - a disjointed subtype

outer join

not null may be assigned as null in a ___

ERP - >100 users, GB-TB

ntegrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources)

All primary key entries are unique, and no part of a primary key may be ____

null

Ways Databases are Classified

number of users database locations expected type and extent of use

Structured Data

numbers, text , dates

The most likely data type for a surrogate key is ____.

numeric

The ____ model is said to be a semantic data model.

object-oriented

The ____ model uses the concept of inheritance.

object-oriented

Redundant relationships

occur when there are multiple (unnecessary) relationship paths between related entities.

Every subtype can have ____ supertype(s) to which it is directly related.

only one

Within a specialization hierarchy, every subtype can have ____ supertype(s) to which it is directly related.

only one

Natural join

only the 10 rows that have arrows drawn will be returned

Software

operating system, DBMS, and application programs and utility

Most decision-support data are based on historical data obtained from ____.

operational

a(n) __ database is designed to support a company's day-to-day operations a. desktop c. enterprise b. workgroup d. transactional

operational

most decision-support data are based on historical data obtained from __ a. operational databases c. enterprise databases b. data warehouses d. workgroup databases

operational databases

Participation is ____________________ if one entity occurrence does not require a corresponding entity occurrence in a particular relationship.

optional

Database

organized collection of logically related data

ORDER BY

organizes data

specialization hierarchy

organizes supertypes and subtypes. this depicts the arrangement of higher-level entity supertypes (parent entities) and lower-level entity subtypes (child entities).

Dependencies based on only a part of a composite primary key are called __ dependencies.

partial

Dependencies based on only a part of a composite primary key are called ____ dependencies.

partial

____________________ completeness means that not every supertype occurrence is a member of a subtype.

partial

If a table has multiple candidate keys and one of those candidate keys is a composite key, the table can have ____ based on this composite candidate key, even when the primary key chosen is a single attribute.

partial dependencies

A dependency based on only a part of a composite primary key is called a(n) ____________________.

partial dependency

__ relates to the activities that make the database perform more efficiently in terms of storage and access speed (a)Performance tuning (c)Query access (b)Database design (d)Database management

performance tuning

Internal schema

physical

The preferred placement for a foreign key when working with a 1:1 relationship is to ____.

place the foreign key in one of the entities

Subquery technique

placing an inner query ( select from where ) within a where or having clause of another (outer) query

Subquery-

placing an inner query (SELECT statement) inside an outer query

One important inheritance characteristic is that all entity subtypes inherit their ____ key attribute from their supertype.

primary

Since it is used to link the tables that originally were related in a M:N relationship, the composite entity structure includes—as foreign keys—at least the ____ keys of the tables that are to be linked.

primary

The most important characteristic of an entity is its ____ key, used to uniquely identify each entity instance

primary

An attribute that is part of a key is known as a __ attribute.

prime

An attribute that is part of a key is known as a(n) ____ attribute.

prime

Existence-Dependent

property of an entity whose existence depends on one more other entities.

Data Dictionary

provides a detailed description of all tables in the database created by the user and designer

WHERE

pulls data based on at least one attribute's specific value

FROM

pulls data from specified table

not exist

queries containing the keyword ____ will return a result table when no rows are found that satisfy the subquery

The response of the DBMS to a query is the ____.

query result set

the response of the DBMS to a query is the __ a. ad hoc query c. query result set b. ad hoc response d. integrated view of the data

query result set

End-user data is ____.

raw facts of interest to the end-user

end-user data is __ a. raw facts about the end-user b. raw facts of interest to the end-user c. data about data d. accurate, relevant and timely information

raw facts of interest to the end-user

Data

raw facts, building blocks of information

Natural Key

real world identifier used to uniquely ID real-world objects. Familiar to end users and forms part of their day-to-day business vocab

a __ is a logically connected set of one or more fields that describes a person, place, or thing (a) database (c) record (b)column (d)file

record

Recovery via rollback/rollforward

recovering a database by restoring the last full backup, and then using data stored in a transaction log to modify the database as needed by either adding transactions (rollforward) or removing erroneous transactions (rollback)

The Chen notation identifies the weak entity by using a double-walled entity ____.

rectangle

right outer join

referential integrity is being enforced

database system

refers to an organization of components that define and regulate the collection, storage, management, and use of data within a database environment

Database design

refers to the activities that focus on the design of the database structure that will be used to store and manage end-user data.

Performance tuning

relates to the activities that make the database perform more efficiently in terms of storage and access speed

The logical view of the relational database is facilitated by the creation of data relationships based on a logical construct known as a(n) ____________________.

relation

MySQL is an example of a(n) ____.

relational data model

A(n) ____________________ is a representation of the relational database's entities, the attributes within those entities and the relationships between those entities.

relational diagram

A ____ is a textual representation of the database tables where each table is listed by its name followed by the list of its attributes in parentheses.

relational schema

A verb associating two nouns in a business rule translates to a(n) ____ in the data model.

relationship

A(n) ____ is bidirectional.

relationship

According to the data modeling checklist, ____ should clearly define participation and cardinality rules.

relationships

DELETE

removes records (deletes a row from a table)

A ____ derives its name from the fact that a group of multiple entries of the same type can exist for any single key attribute occurrence.

repeating group

A relational table must not contain a __.

repeating group

A relational table must not contain a(n) ____.

repeating group

A(n) ____________________ derives its name from the fact that a group of multiple entries of the same type can exist for any single key attribute occurrence.

repeating group

Crow's Foot

representation of the entity relationship diagram using three-pronged symbol to represent the "many" sides of the relationship

Extensible Markup Language (XML)

represents data elements in textual format

extended entity relationship model (EERM)

result of adding more semantic constructs to the original entity relationship model

query result set

results of the query

catalog views

return info used by the SQL server database engine

SELECT

returns information from server

A __ lock locks a segment of the hard disk/volume hosting part of the database.

row-level

Data redundancy

same data stored unnecessarily in different places

The ____________________ is the conceptual organization of the entire database as viewed by the database administrator.

schema

A ____ key is defined as a key that is used strictly for data retrieval purposes.

secondary

security complaint

XML data is __ a. structured c. unstructured b. multistructured d. semistructured

semistructured

XML data is ____

semistructured

most data you encounter is best classified as __ a. structured c. unstructured b. semistructured d. historical

semistructured

Manual file systems

served as a data repository for small data collections. Cumbersome for large collections

SQL

set oriented language

Database

shared, integrated computer structure that stores a collection of end-user data and metadata.

Homonyms

similar-sounding words with different meanings, or a word that with different meanings Ex. Boar and Bore Fair (just & festival)

A desktop database is a ____ database.

single-user

a desktop database is a __ database a. single-user c. workgroup b. multiuser d. distributed

single-user

DBMS

software for managing the database

Application programs

software using the data

The ____ depicts the arrangement of higher-level entity supertypes (parent entities) and lower-level entity subtypes (child entities).

specialization hierarchy

The relationships depicted within the ____ are sometimes described in terms of "is-a" relationships.

specialization hierarchy

two

sql has __ ways to use select for combining data from related tables

Data

stored representations of meaningful objects and events.

Database

storehouse of the data

Data warehouse

stores data used for tactical or strategic decisions

__ data are the result of formatting to facilitate storage, use and generation of information a. Structured c. Unstructured b. Semistructured d. Historical

structured

___ data are the result of formatting to facilitate storage, use and generation of information.

structured

set-oriented language

subqueries are a prime example of why SQL is a

nested queries

subqueries are also called

where

subqueries are not limited to _____ clause but from clause to create a temporary derived table

The ____________________ defines the portion of the database "seen" by the application programs that produce information from the data.

subschema

A(n) ____ is the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

subtype discriminator

Overlapping subtypes are subtypes that contain ____ subsets of the supertype entity set.

subtypes

disjoint constraints

subtypes that are unique. Example a pilot is a unique type of employee. Shown as a closed circle with a (d)

overlapping constraints

subtypes that contain nonunique subsets of the supertype entity set. Example student and employee or both. Shown as a closed circle with an (o)

Operational database

supports a company's day-to-day operations also known as an online transaction processing (OLTP), transactional, or production database

Multi-user database (workgroup database)

supports multiple users at the same time (workgroup and enterprise)

Single-user database (desktop database)

supports only one user at a time (desktop)

outer join

syntax do not easily apply to a join condition of more than two tables

system

compatibility views

system tables from earlier release of SQL server

the relational model's creator, E. F. Codd, used the term relation as a synonym for ____.

table

result or answer table

table created by the query is called the

end transaction or commit work

takes the contents of the log file and applied them to the database, thus making the changes permanent and then empties the log file

An example of denormalization is using a ____ denormalized table to hold report data. This is required when creating a tabular report in which the columns represent data that is stored in the table as rows.

temporary

A ____ relationship exists when three entities are associated

tenary

subtype discriminator

the attribute in the supertype entity that determines to which entity subtype each supertype occurrence is related.

Subtype DISCRIMINATOR

the attribute in the supertype entity that is used to determine to which entity subtype the supertype occurrence is related

generalization

the bottom-up process of identifying a higher level, more generic entity supertype from lower-level entity subtypes

Attribute Domain

the construct used to organize and describe an attribute's set of possible values

entity subtype

the entity supertype contains common characteristics and the entity subtypes contain unique characteristics of each entity subtype. Example employee and pilot

DBMS

the intermediary between the user and the database

Granularity refers to __.

the level of detain represented by the values stored in a tables row

Transactions are interleaved means

the operating system switches cpu services among tasks

Synonyms

the opposite of a homonym, and indicates the use of different names to describe the same attribute

Foreign Key

the primary key of one table used to establish a relationship with instances of a second table

Normalization

the process for evaluating and correcting table structures to - minimize data redundancies - reduce likelihood of data anomalies - minimize and/or eliminate data integrity problems

Structured data

the result of formatting unstructured data to facilitate storage, use, and the generation of information

Determination

the state in which knowing the value of one attribute makes it possible to determine the value of another

specialization

the top-down process of identifying lower-level, more specific entity subtypes from a higher-level entity supertype

Functional Dependence

the value of one or more attributes determines the value of one or more other attributes Ex. Invoice # - Products/Customer CustomerID - Last Name/First Name Banner ID - Last Name/First Name

overlapping subtype

these contain nonunique subsets of the supertype entity set; that is, each entity instance of the supertype may appear in more than one subtype.

subtype discriminator

this is the attribute in the supertype entity that determines to which subtype the supertype occurence is related.

total completeness

this means that every supertype ocurence must be a member of at least one subtype

fan trap

this occurs when you have one entity in two 1:M relationships to other entities, thus producing an association among the other entities that is not expressed in the model.

time-variant data

this refers to data whose values change over time and for which you must keep a history of the data changes

partial completeness

this specifies whether each entity supertype occurence must also be a member of at least one subtype.

to be safe, use the IN operator than ___ when writing queries

derived table

to display both average standard price and standard price the ______ is used

INTERSECT

to find the elements in common between two sets

MINUS

to find the elements in one set that are not in another set

join technique

to include data from subquery_____ is used

A(n) ____ database is designed to support a company's day-to-day operations

transactional

A __ exists when there are functional dependencies such that Y is a functional dependent on X and Z is functional dependent on Y, and X is the primary key.

transitive dependency

A ____ exists when there are functional dependencies such that Y is functionally dependent on X and Z is functionally dependent on Y, and X is the primary key.

transitive dependency

A(n) ____ exists when there are functional dependencies such that Y is functionally dependent on X and Z is functionally dependent on Y, and X is the primary key.

transitive dependency

A composite identifier is a primary key composed of more than one attribute.

true

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.

true

As rare as 1:1 relationships should be, certain conditions absolutely require their use.

true

It is possible for a table in 2NF to exhibit transitive dependency, where one or more nonprime attributes functionally determine other nonprime attributes.

true

Some designs use redundant relationships as a way to simplify the design.

true

The entity supertype contains the common characteristics and the entity subtypes contain the unique characteristics of each entity subtype.

true

The practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.

true

a data warehouse can store data derived from many sources

true

data constitute the building blocks of information

true

data processing can be as simple as organizing data to reveal patterns

true

historically, a manual file system was composed of a system of file folders and filing cabinets

true

initially the files within a computer file system were similar to manual files

true

metadata present a more complete picture of the data in the database than the data itself

true

one disadvantage of a database system over previous data management approaches is increased costs

true

the only way to access the data in the database is through the DBMS

true

the same data might be simultaneously structured and unstructured depending on the intended processing

true

true or false....M:N relationships are not appropriate in a relational model.

true

we are now said to be entering the "knowledge age"

true

with partial dependencies, data redundancies occur because every row entry requires duplication of data.

true

In an ER diagram, primary keys are indicated by ____.

underlining

better design query

understand how indexes are used in query processing keep optimizer statistics up to date use compatible data types for fields and literal in queries write simple queries break complex queries into multiple simple parts dont nest one query inside another query dont combine a table with itself create temporary tables for groups of queries combine update operations retrieve only the data you need dont have the DBMS sort without an index learn! consider the total query processing time for ad hoc queries

outer join

union and not exists can be used in place of

A(n) ____________________ index is an index in which the index key can have only one pointer value (row) associated with it.

unique

Non-overlapping subtypes are subtypes that contain a(n) ____ subset of the supertype entity set.

unique

The "____" characteristic of a primary key states that: The PK must uniquely identify each entity instance. A primary key must be able to guarantee unique values. It cannot contain nulls.

unique values

__ data exist in a format that does not lend itself to processing that yields information a. Structured c. Unstructured b. Semistructured d. Historical

unstructured

__ data exist in the format in which they were collected a. Structured c. Unstructured b. Semistructured d. Historical

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