Quiz 6
________ use the result of the outer query to determine the processing of the inner query. Correlated subqueries Outer subqueries Inner subqueries Subqueries
Correlated subqueries
An equi-join is a join in which one of the duplicate columns is eliminated in the result table. True or False
False
Subqueries can only be used in the WHERE clause. True or False
False
A correlated subquery is executed once for each iteration through the outer loop. True or False
True
A join in which the joining condition is based on equality between values in the common column is called a(n) equi-join. True or False
True
A natural join is the same as an equi-join, except that it is performed over matching columns that have been defined with the same name, and one of the duplicate columns is eliminated. True or False
True
An SQL query that implements an outer join will return rows that do not have matching values in common columns. True or False
True
The ________ clause is used to combine the output from multiple queries into a single result table. INTERSECT DIVIDE COLLATE UNION
UNION
A join in which the joining condition is based on equality between values in the common columns is called a(n): equi-join. unilateral join. natural join. both equi-join and natural join.
both equi-join and natural join.
A join operation: brings together data from two different fields. causes two tables with a common domain to be combined into a single table or view. causes two disparate tables to be combined into a single table or view. is used to combine indexing operations.
causes two tables with a common domain to be combined into a single table or view.
A ________ is a temporary table used in the FROM clause of an SQL query. correlated subquery derived table view table None of these
derived table
A join that is based upon equality between values in two common columns with the same name and where one duplicate column has been removed is called a(n): equi-join. natural join. multivariate join. inner join.
natural join.
A join in which rows that do not have matching values in common columns are still included in the result table is called a(n): natural join. equi-join. outer join. union join.
outer join.
A type of join where a table is joined to itself is called a(n): unary join. self-join. unnatural join. pinned join.
self-join.
A type of query that is placed within a WHERE or HAVING clause of another query is called a: master query. subquery. superquery. multi-query.
subquery.