5010 Midterm

when different categories of a table's rows are processed separately.

Horizontal partitioning makes sense:

False

Horizontal partitioning refers to the process of combining several smaller relations into a larger table.

application programs.

In a file processing environment, descriptions for data and the logic for accessing the data are built into:

supertypes

In a supertype/subtype hierarchy, subtypes that are lower in the hierarchy inherit attributes from not only their immediate supertype but from all ________ in the hierarchy.

True

In the figure shown below, there could be an instance of a rental unit that is neither an apartment nor a house.

Each vendor can supply many parts to any number of warehouses, but need not supply any parts.

In the figure shown below, which of the following business rules would apply? PART VENDOR SUPPLYSCHEDULE WAREHOUSE

Both Each patient has one or more patient histories and Each patient history belongs to one and only one patient

In the following diagram, which of the answers below is true? PATIENT||----|<PatientHistory

False

In the relational data model, associations between tables are defined through the use of primary keys.

provide rapid random and sequential access to base-table data.

Indexes are created in most RDBMSs to:

True

Indexes are most useful for columns that frequently appear in WHERE clauses of SQL commands, either to qualify the rows to select or for linking.

True

Keeping the zip code with the city and state in a table is a typical form of denormalization.

True

Metadata are data that describe the properties of other data.

True

Multitier client/server database applications contain a business logic layer.

file descriptors being stored in each application.

Program-data dependence is caused by:

True

The ALTER TABLE command is used to change a table definition.

False

The DROP command deletes rows from a table individually or in groups.

create view

The SQL command ________ defines a logical table from one or more tables or views.

schema

The ________ is the structure that contains descriptions of objects such as tables and views created by users.

partial specialization

The ________ rule specifies that an entity instance of a supertype is allowed not to belong to any subtype.

create schema.

The command for creating a database is:

False

The disjoint rule specifies that if an entity instance of the supertype is a member of one subtype, it MUST simultaneously be a member of another subtype.

no primary key attribute can be null.

The entity integrity rule states that:

field.

The smallest unit of application data recognized by system software is a:

data integrity

The storage format for each attribute from the logical data model is chosen to maximize ________ and minimize storage space.

derived

The total quiz points for a student for an entire semester is a(n) ________ attribute.

False

Unlike columns, the rows of a relation may not be interchanged and must be stored in one sequence.

Changes the unit price of Product 7 to 775

What does the following SQL statement do? Update Product_T Set Unit_Price = 775 Where Product_ID = 7

The average Standard_Price of all products in Product_V

What result will the following SQL statement produce? Select Avg(standard_price) as average from Product_V;

All of these

Which of the following are anomalies that can be caused by redundancies in tables?

Count

Which of the following counts ONLY rows that contain a value?

a one-to-many relationship.

All of the following are common denormalization opportunities EXCEPT:

use a lot of storage space.

All of the following are objectives when selecting a data type EXCEPT:

maximize storage space.

All of the following are the main goals of normalization EXCEPT:

composite identifier.

An attribute that uniquely identifies an entity and consists of a composite attribute is called a(n):

All of these.

An entity cluster can be formed by:

False

An entity type on which a strong entity is dependent is called a covariant entity.

data replication.

Another form of denormalization where the same data are stored in multiple places in the database is called:

drop

Any create command may be reversed by using a ________ command.

False

Data redundancy is used to establish relationships between data but is never used to improve database performance.

True

Expressions are mathematical manipulations of data in a table that may be included as part of the SELECT statement.

You must specify the fields to insert if you are only inserting some of the fields.

Given a table named store with 5 fields: store_id, address, city, state, zipcode, why would the following insert command not work? insert into store values ('234 Park Street')

completeness

A ________ constraint is a type of constraint that addresses whether an instance of a supertype must also be an instance of at least one subtype.

the key must indicate the row's position in the table.

A candidate key must satisfy all of the following conditions EXCEPT:

True

A cascading delete removes all records in other tables associated with the record to be deleted.

hashing algorithm

A(n) ________ is a routine that converts a primary key value into a relative record number.

False

A default value is the value that a field will always assume, regardless of what the user enters for an instance of that field.

data type.

A detailed coding scheme recognized by system software for representing organizational data is called a(n):

False

A member of a subtype does NOT necessarily have to be a member of the supertype.

All of these.

A method for handling missing data is to:

True

A multivalued attribute may take on more than one value for a particular entity instance.

composite key.

A primary key that consists of more than one attribute is called a:

False

A referential integrity constraint specifies that the existence of an attribute in one table depends upon the existence of a foreign key in the same or another table.

mandatory one

A relationship where the minimum and maximum cardinality are both one is a(n) ________ relationship.

ternary

A simultaneous relationship among the instances of three entity types is called a(n) ________ relationship.

a logical description of some portion of the database.

A user view is:

functional dependency.

A constraint between two attributes is called a(n):

True

A data model is a graphical system used to capture the nature and relationships among data.

Select min(standard_price) from Product_V;

Which of the following will produce the minimum of all standard prices?

Hashed

Which type of file is easiest to update?

False

With the traditional file processing approach, each application shares data files, thus enabling much data sharing.