Database Administration Flashcards
7 cards from real CPA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Database Administration flashcards as text
Which SQL clause is used to filter rows after aggregation has been applied?
Answer: HAVING
HAVING filters groups produced by GROUP BY, whereas WHERE filters individual rows before aggregation.
A table has no primary key defined. Which term best describes such a table?
Answer: Heap table
A heap table is a table stored without any ordered index or defined primary key, resulting in unordered row storage.
Which isolation level prevents dirty reads but still allows non-repeatable reads?
Answer: Read Committed
Read Committed prevents dirty reads by only seeing committed data, but another transaction can modify the row between two reads in the same transaction.
What does the SQL keyword DISTINCT do in a SELECT statement?
Answer: Removes duplicate rows from the result
DISTINCT eliminates duplicate rows from the query result so each unique combination of selected columns appears only once.
Which type of database index is most efficient for range queries on a column?
Answer: B-tree index
B-tree indexes maintain sorted order, making them ideal for range queries using operators like BETWEEN, .
In a relational database, what is a composite key?
Answer: A key made up of two or more columns
A composite key uses two or more columns together to uniquely identify a row when no single column is sufficient.
Which SQL command permanently removes a table and all its data from the database?
Answer: DROP
DROP TABLE removes the table definition and all its data, indexes, and constraints permanently from the database.