Database Management & Information Systems Flashcards

Which normal form eliminates transitive dependencies in a relational table?

Answer: Third Normal Form (3NF)

3NF removes transitive dependencies by ensuring every non-key attribute depends only on the primary key.

In a client-server database architecture, where is the DBMS engine typically located?

Answer: On the server

In client-server architecture, the DBMS engine runs on the server and processes queries sent by client applications.

What does a ROLLBACK statement do in a database transaction?

Answer: Undoes all changes made since the last COMMIT

ROLLBACK reverses all data modifications made during the current transaction, restoring the database to its prior state.

Which type of JOIN returns only the rows that have matching values in both tables?

Answer: INNER JOIN

An INNER JOIN returns only records where there is a match in both joined tables.

What is the purpose of an index in a relational database?

Answer: To speed up data retrieval operations

Indexes create a separate data structure that allows the DBMS to locate rows faster without scanning the entire table.

In the E-R model, a relationship in which one entity can be associated with many instances of another entity, but each instance of the second can relate to only one of the first, is called:

Answer: One-to-many

A one-to-many (1:N) relationship means one record in table A can link to multiple records in table B, but each B record links to only one A record.

Which SQL clause is used to filter groups after a GROUP BY operation?

Answer: HAVING

HAVING filters the result of GROUP BY aggregations, whereas WHERE filters individual rows before grouping.