Question 1

Query by Example (QBE) requires the end user to be able to construct a complex SQL Statement.

Accepted Answer

QBE allows end users to create queries without knowing SQL.

Question 2

A horizontal subset includes only some of the rows in the table and all of the table's columns.

Accepted Answer

A horizontal subset refers to selecting specific rows from a table while retaining all columns, as opposed to a vertical subset, which would involve selecting specific columns.

Question 3

Relational Algebra allows for multiple operations in a single query.

Accepted Answer

A separate query must be written for each operation in relational algebra.

Question 4

A Microsoft Access dynaset looks and behaves like a table but is not stored as a table.

Accepted Answer

A dynaset in Microsoft Access is a dynamic set of data that results from a query, appearing like a table but not stored as one. It reflects changes in the underlying data.

Question 5

Ad hoc querying is done primarily by professional database developers who use SQL.

Accepted Answer

Ad hoc querying is typically done by end users.

Question 6

You can perform a right outer join on tables that do not share a common field.

Accepted Answer

Tables must share a common field to be joined with any type of join.

Question 7

A full outer join will show records that contain NULL values.

Accepted Answer

A full outer join returns all records from both tables, with NULLs in place where there is no match.

Question 8

The following tables cannot be joined:

Accepted Answer

The tables share Dept ID therefore they can be joined.

Question 9

The criteria field in the query design for Microsoft Access accepts Relational Algebra language syntax.

Accepted Answer

Mathematical comparison or logical operators are used in the criteria field.

Question 10

A query in Microsoft Access takes a subset of data contained in a table and creates another table on which you can perform multiple queries.

Accepted Answer

A query in Microsoft Access generates a view, which looks like a table but isn't a table.

Question 11

Microsoft Access uses only a QBE method for query creation.

Accepted Answer

Queries may also be formulated in SQL in Microsoft Access.

Question 12

Every SQL statement begins with the word PROJECT.

Accepted Answer

SQL statements begin with the word SELECT.

Question 13

The SELECT component of a SQL query statement specifies which attributes are to be included in the answer to the query.

Accepted Answer

The SELECT component of a SQL query is used to specify the columns (attributes) that should be returned in the result set of the query.

Question 14

An SQL query statement that accomplishes only the relational algebra PROJECT operation would not include a WHERE clause.

Accepted Answer

The PROJECT operation in relational algebra is used to select specific columns from a table, which corresponds to the SELECT clause in SQL without a WHERE clause.

Question 15

A single SQL query statement can accomplish relational algebra select, project, and join operations.

Accepted Answer

A single SQL query can perform select (filtering rows), project (selecting columns), and join (combining tables) operations, which correspond to relational algebra operations.

Question 16

Right outer join queries can only be created in relational algebra.

Accepted Answer

Right outer join queries can be created in structured query language and in QBE.

Question 17

The answer to a query connecting two criteria with an AND logical operator will include all instances that meet either of the two criteria.

Accepted Answer

The answer will contain only the instances that meet both criteria.

Question 18

A calculation that performs a mathematical operation within a single column of data is called an aggregation function.

Accepted Answer

An aggregation function is a calculation that performs a mathematical operation on a set of values, and returns a single value. This operation can be performed on a single column of data, or on multiple columns of data.

Question 19

SUM, MAX, and COUNT are examples of aggregation functions that may be included in both SQL and QBE queries.

Accepted Answer

Aggregation functions like SUM, MAX, and COUNT are commonly used in both SQL (Structured Query Language) and QBE (Query By Example) to perform calculations on a set of values and return a single value.

Question 20

A parameter query requires a user to change the design of the query to reuse it with new parameter values.

Accepted Answer

A parameter query allows the user to enter new parameter values without changing the query design.

Quiz 7: Information Retrieval From Relational Databases