DataBase Test 2/Midterm 3330

"All of the following are true about the use of AND and OR operators in an SQL SELECT command, except ____."

"either the AND or the OR operator may be used in a given SQL SELECT command, but not both "

"All of the following are SQL commands, except ____."

CREATE SELECT

"In the SQL SELECT command, the table(s) involved in the query is (are) specified in the ____ clause."

FROM

"For the nested-loop join to work, each of the two join attributes either has to be in sorted order or has to have an index built over it."

False

"If the referential integrity delete rule between two relations is cascade, the deletion of a record in the relation on the many side of the one-to-many relationship may result in the deletion of one or more records in the relation on the one side of the relationship."

False

"If the referential integrity delete rule between two relations is restrict, the deletion of a record in the relation on the one side of the one-to-many relationship may result in the deletion of one or more records in the relation on the many side of the relationship."

False

"In a one-to-many binary relationship, the primary key from the many side of the relationship is inserted as a foreign key in the one side of the relationship."

False

"In a relational Join operation, the join attributes must have the same attribute names."

False

A one-to-one binary relationship in an E-R diagram can be converted into either one or two tables in a relational database.

True

Search arguments appear in the SQL SELECT command WHERE clause.

True

Structured Query Language (SQL) is _____.

both a data definition language and a data manipulation language

The SQL SELECT HAVING clause limits the output of a GROUP BY operation based on ____.

calculated values of the built-in functions

Structured query language is capable of _____.

creating new tables creating indexes on tables dropping tables.

Placing SQL SELECT commands among the lines of a higher-level language program if referred to as ____.

embedded

"If two relations represent a one-to-many binary relationship, the primary key of the relation on the one side of the relationship is inserted into the relation on the many side of the relationship as a _____."

foreign key

A primary key of one relation appearing in another relation of the database is called a _____ in the other relation.

foreign key

"All of the following are true if a relational database is in third normal form, except each of the tables of the database is _____."

in every normal form higher than third normal form

The relational Join operator is capable of _____.

integrating the data in two relations

"The combination of the relational Select, Project, and Join operators is capable of _____."

integrating the data in two relations and then narrowing the search to as little as a single cell or data value

Storing a unary one-to-many relationship in a relational database _____.

involves adding one column to a relation

The SQL SELECT LIKE operator ____.

involves the use of wildcards

Storing a one-to-one binary relationship in a relational database _____.

is accomplished with a foreign key

A relational table in third normal form _____.

is free of data redundancy

A subquery can be used in place of a(n) ____.

join

A relational query optimizer optimizes the _____.

manner in which a query is solved

A relational query optimizer optimizes ____.

the performance of a relational query

The conversion of a ternary relationship into relational tables will result in a total of _____ tables.

4

The SQL SELECT built-in function that returns the number of rows of a table that match a given attribute value is _____.

COUNT

"In an equijoin, one of the two identical join columns in the result is eliminated."

False

"In converting a one-to-one binary relationship in an E-R diagram into two relational tables, the rule is that the unique identifier of the entity on the many side of the one-to-many relationship is placed as a foreign key in the table representing the entity on the one side. "

False

"In relational database terminology, the terms row and relation are synonymous."

False

"In the SQL SELECT command embedded mode, the user types the command at a workstation and presses the Enter key. The command goes directly to the relational DBMS, which evaluates the query and processes it against the database. "

False

"SQL SELECT commands must be issued against the actual, physical database tables rather than against logical views of the tables."

False

"The OR operator in the SQL SELECT command WHERE clause means one or the other, but not both."

False

"The SQL SELECT command is used to update, insert, and delete rows in relational tables."

False

"The only way to retrieve all of the fields of a table with an SQL SELECT command is to list them all in the SELECT clause."

False

"Today, relational DBMSs have limited commercial use in niche areas only."

False

"When tables are to be joined in an SQL SELECT statement, the join attributes from each table are set equal to each other in the FROM clause."

False

A GROUP BY clause in an SQL SELECT command groups together columns based on common attribute values.

False

A foreign key must have unique values in the relation in which it is a foreign key.

False

A many-to-many unary relationship in an E-R diagram requires the creation of a total of three tables in a relational database.

False

A one-to-one unary relationship in an E-R diagram requires the creation of a total of three tables in a relational database.

False

A relation s primary key field can have non-unique values.

False

A relational query optimizer is a separate piece of software that can be called in by the relational DBMS when it has to respond to an especially complex query.

False

A ternary relationship in an E-R diagram requires the creation of a total of three tables in a relational database.

False

Converting a one-to-one binary relationship in an E-R diagram into a single table in a relational database introduces data redundancy.

False

Converting from first to second normal form involves subdividing tables to remove transitive dependencies.

False

First normal form tables are free of data redundancy.

False

Intersection data in a relational database is stored in one of the two relations representing the entities in the many-to-many relationship.

False

Logical database design is the process of modifying the physical database design to improve performance.

False

Multivalued attributes are not permitted in unnormalized data.

False

Only two tables can be joined in an SQL SELECT statement.

False

Referential integrity in a relational database refers to problems associated with redundant data within a single relation.

False

Referential integrity is a factor in record deletion but not in record insertion or update.

False

Representing a unary many-to-many relationship in a relational database requires the addition of one column to the relation that represents the single entity involved in the relationship.

False

The BETWEEN operator in the SQL SELECT command WHERE clause requires that a character string must be between two specified character strings.

False

The Bill of Materials problem is an example of a ternary relationship.

False

The Bill of Materials problem is an example of a unary one-to-many relationship.

False

The data normalization process is known as a composition process.

False

The data normalization process is progressive. If a group of tables is in second normal form it is also in third normal form.

False

The determinant of an attribute must always be a single attribute.

False

The only way to retrieve all of the fields of a table with an SQL SELECT command is to list them all in the SELECT clause.

False

The relational Project operator retrieves one or more rows from a relation.

False

The relational Select operator retrieves one or more columns from a relation.

False

The two primary keys representing the entities in the many-to-many relationship will always serve as the primary key in the additional relation representing the many-to-many relationship.

False

The use of a subquery in an SQL SELECT statement is always optional.

False

The SQL SELECT operator that finds rows with equal values of a given attribute and allows the built-in functions to operate on them is _____.

GROUP BY

The SQL SELECT built-in function COUNT ____.

None of the above

The primary key of the additional relation needed to store a ternary relationship _____.

None of the above

"In a relational database, a logical view ____."

None of the above.

"The conversion of a unary one-to-one relationship, a unary one-to-many relationship, and a unary many-to-many relationship, into relational tables have in common _____."

None of the above.

The SQL SELECT ORDER BY operator ____.

None of the above.

"In the SQL SELECT command, the attributes to be retrieved are specified in the ____ clause."

SELECT

The SQL SELECT built-in function that adds the values of a specified set of attributes is ____.

SUM

Which of the following is true about determinants?

They can consist of single or multiple attributes.

"Depending on the circumstances, it is possible that a foreign key is part of the primary key of the relation in which it is a foreign key."

True

"If the referential integrity delete rule between two relations is cascade, the deletion of a record in the relation on the one side of the one-to-many relationship may result in the deletion of one or more records in the relation on the many side of the relationship."

True

"If the referential integrity delete rule between two relations is restrict, an attempt to delete a record in the relation on the one side of the one-to-many relationship will be rejected if one or more records in the relation on the many side of the relationship has the record s primary key value as its/their foreign key value."

True

"In a relational Join operation, the join attributes must have the same domain of values."

True

"In an SQL SELECT statement, a subquery can accomplish the same function as a join."

True

"In first normal form a single, generally multi-attribute, key is chosen that defines or determines all of the other attributes."

True

"In relational database management, data integration takes place at the time that a relational query is processed."

True

"In third normal form, all foreign keys appear where needed to logically tie together related tables."

True

"Once a GROUP BY clause in an SQL SELECT command groups together rows based on common attribute values, a built-in function can produce a result for each group."

True

"The SQL SELECT command is capable of executing relational Select, Project, and Join operations, singly or in combination."

True

"When a subquery is present in an SQL SELECT statement, the subquery is executed before the main query."

True

A basic SQL SELECT command is capable of performing a combination of relational Select and Project operations.

True

A basic SQL SELECT command is capable of retrieving a single column value from a single row of a table.

True

A group of tables is said to be in a particular normal form if every table in the group is in that normal form.

True

A many-to-many binary relationship in an E-R diagram requires the creation of a total of three tables in a relational database

True

A many-to-many binary relationship in an E-R diagram requires the creation of a total of three tables in a relational database.

True

A one-to-many unary relationship in an E-R diagram can be handled within a single table in the conversion to a relational database design.

True

A one-to-one binary relationship can utilize a foreign key in much the same way as a one-to-many binary relationship.

True

A referential integrity problem can result in a foreign key value in one relation having no corresponding match in the primary key of another relation.

True

A relational DBMS s relational query optimizer obtains the information it needs about the database from the DBMS s relational catalog.

True

A simple entity box in an E-R diagram is converted into a relation table in a relational database.

True

A ternary relationship may have intersection data associated with it.

True

All of the data involved in a one-to-one binary relationship could be combined in one relation.

True

All of the standard comparison operators can be use in the SQL SELECT command WHERE clause.

True

Converting from first to second normal form involves subdividing tables to remove partial functional dependencies.

True

Data normalization is a methodology for organizing attributes into tables so that redundancy among the non-key attributes is eliminated.

True

In first normal form tables every attribute value is atomic, that is no attribute is multi-valued.

True

Performance issues delayed the introduction of relational database management systems as viable commercial products.

True

Referential integrity involves two relations logically associated (by foreign keys).

True

Representing a unary one-to-many relationship in a relational database requires the addition of one column to the relation that represents the single entity involved in the relationship.

True

SQL has commands that are capable of creating and dropping indexes on relational tables.

True

SQL incorporates features of both a data definition language and a data manipulation language.

True

Storing a many-to-many relationship in a relational database requires the creation of an additional relation.

True

Storing a ternary relationship in a relational database requires the creation of an additional relation.

True

The DISTINCT operator in the SQL SELECT command removes duplicate rows from a query result.

True

The DISTINCT operator in the SQL SELECT command removes duplicate rows from a query result..

True

The HAVING clause limits the results of a GROUP BY clause based on the values calculated for each group with the built-in functions.

True

The LIKE operator in the SQL SELECT command WHERE clause allows the use of wildcards to substitute for character strings.

True

The ORDER BY operator in the SQL SELECT command orders a query result s output rows by a set of attribute values.

True

The domain of values of the new column added to the relation to represent the unary one-to-many relationship is the same as that of the relation s primary key.

True

The emergence of the personal computer influenced the emergence of relational database management.

True

The input to the data normalization process is a list of the attributes in the database and a list of the functional dependencies among them.

True

The relational Join operation accomplishes data integration in a relational database.

True

The tables used in a SELECT command are listed in the FROM clause.

True

The two major logical database design techniques are conversion of E-R diagrams to relational tables and data normalization.

True

"In the SQL SELECT command, the search arguments that limit the rows involved in the query are specified in the ____ clause."

WHERE

"In the SQL SELECT command, a simple Select operation designed to retrieve one or more entire rows of a single table is characterized by _____."

a * in the SELECT clause and one or more predicates in the WHERE clause

"If there is a one-to-many relationship between two entities, S (on the one side of the relationship) and T (on the many side of the relationship), and the delete rule between the two relations that represent them in a relational database is restrict, deleting a record in relation S _____."

a and b

"If there is a one-to-many relationship between two entities, S (on the one side of the relationship) and T (on the many side of the relationship), and the delete rule between the two relations that represent them in a relational database is set-to-null, deleting a record in relation S _____."

a and c

"In the SQL SELECT command, a simple Project operation designed to retrieve one or more columns (for all rows) of a single table is characterized by _____."

a list of attributes in the SELECT clause and the absence of a WHERE clause

Data normalization is _____.

a logical database design technique

An access path is _____.

a plan for the steps to take to respond to an SQL query

"As opposed to the fields of a file, the columns of a relation _____."

can be arranged in any order although it will affect the meaning of the data

Referential integrity problems _____.

can occur in relational databases

A relational table in first normal form _____.

cannot have multivalued attributes

A relational table in second normal form _____.

may have transitive dependencies

The column added to a relation to store a unary one-to-many relationship _____.

must have the same domain of values as the primary key

A join in which one of two identical join columns is eliminated from the result is called a(n) _____.

natural join

Typing SQL SELECT commands in at a keyboard and sending them directly to the relational DBMS for processing is referred to as ____.

query mode

"In an SQL SELECT command, a SELECT clause with several attributes and the absence of a WHERE clause indicates a(n) ____."

relational Project operation

Storing a ternary relationship in a relational database _____.

requires the creation of an additional relation

Storing a unary many-to-many relationship in a relational database _____.

requires the creation of an additional relation

The SQL SELECT command is used to ____ a relational database.

retrieve data from

The relational Select operator is capable of _____.

retrieving one or more rows from a relation

"In SQL, the use of a(n) _____ is capable of obtaining the same result as a Join operation."

subquery

"The conversion of a unary many-to-many relationship, a binary many-to-many relationship, and a ternary relationship, into relational tables have in common _____."

the addition of one additional table beyond those required for the entities themselves

"All of the following are taken into account by the relational query optimizer to do its job, except _____."

the number of COUNT operations in the query

"All of the following features of a relational query or of the relational database that it accesses are considered by the relational query optimizer, except ____."

the number of rows of output the query produces

"All of the following are true regarding logical views or views , except _____."

they require the physical duplication of data into new tables

The SQL SELECT BETWEEN operator is used ____.

to find a numeric value between two numeric values

The purpose of the SQL SELECT GROUP BY clause is ____.

to group together rows of a table with common attribute values in order to perform calculations using the built-in functions on attributes within each group

"In the SQL SELECT command, a Join operation designed to go on to retrieve specific attributes of specific entities is characterized by _____."

two or more tables in the FROM clause with a list of attributes in the SELECT clause and one or more predicates in the WHERE clause

The Bill of Materials problem is stored in a relational database as a _____ relationship.

unary many-to-many

"If there is a one-to-many relationship between two entities, S (on the one side of the relationship) and T (on the many side of the relationship), and the delete rule between the two relations that represent them in a relational database is restrict, deleting a record in relation T _____."

will always be allowed

"If there is a one-to-many relationship between two entities, S (on the one side of the relationship) and T (on the many side of the relationship), and the delete rule between the two relations that represent them in a relational database is cascade, deleting a record in relation S _____."

will be allowed and certain records of relation T may also be deleted.