Database Management Systems Flashcards
6 cards from real B CompE Bachelor of Computer Engineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Database Management Systems flashcards as text
Which normal form eliminates partial dependencies on a composite primary key?
Answer: Second Normal Form (2NF)
2NF removes partial dependencies by ensuring every non-key attribute is fully functionally dependent on the entire primary key.
What SQL clause is used to filter results after aggregation?
Answer: HAVING
The HAVING clause filters grouped results from aggregate functions, whereas WHERE filters individual rows before grouping.
Which type of JOIN returns all rows from both tables, with NULLs where there is no match?
Answer: FULL OUTER JOIN
A FULL OUTER JOIN returns all rows from both tables, filling unmatched columns with NULL values.
What is a foreign key in a relational database?
Answer: A primary key of another table referenced by the current table
A foreign key is a column (or set of columns) in one table that references the primary key of another table to enforce referential integrity.
Which SQL command removes all rows from a table without deleting the table structure?
Answer: TRUNCATE
TRUNCATE removes all rows from a table quickly without logging individual row deletions, while keeping the table structure intact.
What does ACID stand for in database transactions?
Answer: Atomicity, Consistency, Isolation, Durability
ACID stands for Atomicity, Consistency, Isolation, and Durability, four properties that guarantee reliable database transactions.