A182 true and false
A binary relationship is a relationship based on numerical entity instance identifiers.
False
A characteristic of a relation is that the rows of a relation may hold identical values.
False
A constraint that requires an instance of an entity to exist in one relation before it can be referenced in another relation is called an insertion anomaly.
False
A database design is rarely a redesign of an existing database.
False
A database is called "self-describing" because it reduces data duplication.
False
A relation can have only one candidate key.
False
A relation is a three-dimensional table.
False
ANSI standard SQL uses the symbol "%" to represent a series of one or more unspecified characters.
False
An exclusive subtype pattern has one supertype entity that relates to one or more subtype entities.
False
An identifier serves the same role for a table that a key does for an entity.
False
Any table that meets the definition of a relation is in 2NF.
False
Arithmetic in SQL statements is limited to the operations provided by the built-in functions.
False
Business organizations have resisted adopting object-oriented database systems because the cost of purchasing OODBMS packages is prohibitively high.
False
Database design is important, but fortunately it is simple to do.
False
Design guidelines and priorities are the same whether you're working with an updateable database or a read-only database.
False
Every subquery can be alternatively expressed by a join.
False
General-purpose remarks columns rarely contain important data.
False
ID-dependent entities are associated by a nonidentifying relationship.
False
If a table meets the minimum definition of a relation, it has an effective or appropriate structure.
False
In Microsoft Access, you can use the Oracle DBMS in place of the Jet DBMS by using the appropriate "File" command.
False
In a 1:N relationship, the term parent refers to the N side of the relationship.
False
In a database processing system, stored procedures can only reside in the database management system (DBMS).
False
In addition to being a data sublanguage, SQL is also a programming language, like COBOL.
False
In an Enterprise-class database system, a database application accesses the database data.
False
In an Enterprise-class database system, business users interact directly with the DBMS, which directly accesses the database data.
False
In every database, not just the databases discussed in this book, table names are capitalized.
False
In the functional dependency shown as A → B, B is the determinant.
False
Microsoft Access is just a DBMS.
False
Normalization eliminates modification anomalies and data duplication.
False
Normalization is an advantage for a read-only database.
False
One example of a database design using a strong relationship is the multivalued attribute pattern.
False
Paradox is the only major survivor of the "bloodbath of PC DBMS products."
False
Read-only databases are often updated.
False
Relations are classified into "normal forms" based only on the types of modification anomalies that they are vulnerable to.
False
SQL can only query a single table.
False
SQL stands for Standard Query Language.
False
SQL statements are ended with a colon.
False
SQL, although very popular, has never become a national standard.
False
Small databases typically have simple structures.
False
Sorting is specified by the use of the SORT BY phrase.
False
The CODASYL DBTG mode structured data relationships as a tree structure.
False
The DBMS ranked as having the "most power and features" in the text is IBM's DB2.
False
The built-in function SUM can be used with any column type.
False
The columns of a relation are sometimes called "tuples."
False
The functional dependency noted as A → B, means that the value of A can be determined from the value of B.
False
The standard sales order/line item pattern is a classic example of unneeded normalization.
False
To count the number of rows in a table, use the SQL construct COUNT(ROWS).
False
To determine the number and type of columns in a table, use the SQL construct COUNT(*).
False
To eliminate multivalued dependencies, normalize your tables so that they are all in BCNF.
False
To have SQL automatically eliminate duplicate rows from a result, use the keyword DISTINCT with the FROM keyword.
False
When designing a database, first identify the entities, then determine the attributes, and finally create the relationships.
False
When examining data values as a part of assessing table structure, there is no need to try to determine foreign keys.
False
When you are creating a database from existing data, you will have only minor problems with inconsistent values.
False
dBase was the first PC-based DBMS to implement true relational algebra on a PC.
False
A "composite identifier" is defined as a composite attribute that is an identifier.
True
A SELECT statement used in WHERE clause is called a subquery.
True
A WHERE clause can contain another SELECT statement enclosed in parenthesis.
True
A database design may be a new systems development project.
True
A database management system (DBMS) creates, processes and administers databases.
True
A deletion anomaly exists when deleting data about one entity results in the loss of data about another entity.
True
A determinant of a functional dependency may or may not be unique in a relation.
True
A referential integrity constraint limits the values of a foreign key.
True
A relationship's minimum cardinality indicates whether or not an entity must participate in the relationship.
True
A row can be uniquely identified by a key.
True
A tuple is a group of one or more columns that uniquely identifies a row.
True
A weak entity is an entity that cannot exist in the database without (and is logically dependent upon) another type of entity also existing in the database.
True
All relations are tables, but not all tables are relations.
True
All weak entities must have a minimum cardinality of 1 on the entity on which it depends.
True
An alternative to combining tables by a subquery is to use a join.
True
An asterisk (*) following the SELECT verb means that all columns are to be obtained.
True
An attribute that determines which subtype is appropriate is called a discriminator.
True
An entity class is described by the structure of the entities in that class.
True
An entity is something in the users' work environment that the users want to track.
True
Applications are computer programs used directly by users.
True
Attribute Y is functionally dependent on attribute X if the value of attribute X determines the value of Y.
True
Breaking a relation into two relations may create the need for a referential integrity constraint to be defined between the two relations.
True
Creating a read-only database is a job often given to beginning database professionals.
True
Data Language/I (DL/I) structured data relationships as a tree structure.
True
Data is recorded facts and figure; information is knowledge derived from data.
True
Database design varies depending on whether you're building an updateable database or a read-only database.
True
Databases record data in such a way that they can produce information.
True
Denormalization is the process of joining previously normalized tables back together.
True
Functional dependencies can involve groups of attributes.
True
In a database, each table stores data about a different type of thing.
True
In an E-R model, the three types of maximum cardinality are 1:1, 1:N and N:M.
True
In an Enterprise-class database system, a database application interacts with the DBMS.
True
Information systems that stored groups of records in separate files were called file processing systems.
True
Multivalued dependencies show up under a different name as the multivalued, multicolumn problem.
True
Normalization requires applications to use more complex SQL since they will need to write subqueries and joins to recombine data stored in separate relations.
True
Null values are a problem because they are ambiguous.
True
One example of a database design using an ID-dependent relationship is the archetype/instance pattern.
True
One example of a database design using an ID-dependent relationship is the association pattern.
True
SQL commands can be embedded in application programs.
True
SQL was developed by IBM in the late 1970s.
True
Structured Query Language (SQL) is an internationally recognized standard language that is understood by all commercial database management system products.
True
Subtype entities contain only attributes unique to the subtypes.
True
The 1977 edition of this text contained a chapter on the relational model, and that chapter was reviewed by E. F. Codd.
True
The DBMS engine in Microsoft Access is called Jet.
True
The DBMS ranked as being the "most difficult to use" in the text is Oracle Corporation's Oracle.
True
The DBMS ranked as having the "least power and features" in the text is Microsoft Access.
True
The SQL keyword FROM is used to specify the table to be used.
True
The clause SELECT COUNT (*) results in a table with a single row and a single column.
True
The condition in WHERE clauses can refer to a set of values by using the IN keyword.
True
The description of a database's structure that is stored within the database itself is called the "metadata."
True
The essence of normalization is taking a relation that is not in BCNF and breaking it into multiple relations such that each one is in BCNF.
True
The first step in assessing table structure is to count rows and examine columns.
True
The multivalued dependency noted as A →→ B, means that the value of A determines a set of values of B.
True
The presence of one or more foreign keys in a relation means that we cannot eliminate duplicated data in that table.
True
The principle difference between an entity and a table is that you can express a relationship between entities without using foreign keys.
True
The purpose of a database is to help people keep track of things.
True
The rows of the result table can be sorted by the values in one or more columns.
True
The second step in assessing table structure is to examine data values and determine dependencies and keys.
True
The third step in assessing table structure is to check the validity of presumed referential integrity constraints.
True
Two or more tables are joined by giving the table names in the FROM clause and specifying the equality of the respective column names as a condition in the WHERE clause.
True
Undesirable consequences of changing the data in a relation are called "modification anomalies."
True
When examining data values as a part of assessing table structure, you should try to determine functional dependencies.
True
When examining data values as a part of assessing table structure, you should try to determine multivalued dependencies.
True
When you are given a set of tables and asked to create a database to store their data, the first step is to assess the tables' structure and content.
True