Database Systems & SQL Flashcards
6 cards from real B.S.W.E. Bachelor of Software 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 Systems & SQL flashcards as text
What is a transaction in database systems?
Answer: A logical unit of work that must be completed entirely or not at all
A transaction is a sequence of database operations treated as a single logical unit, following ACID properties for reliability.
What is the purpose of the ROLLBACK statement?
Answer: To undo changes made in the current transaction
ROLLBACK undoes all changes made during the current transaction, restoring the database to its state before the transaction began.
What is sharding in database systems?
Answer: Horizontal partitioning of data across multiple database instances
Sharding is a database scaling technique that horizontally partitions data across multiple instances to distribute load and improve performance.
What does ORM stand for in software development?
Answer: Object Relational Mapping
Object Relational Mapping (ORM) converts data between object-oriented programming languages and relational databases automatically.
What is a deadlock in database systems?
Answer: When two or more transactions wait indefinitely for each other's locks
A deadlock occurs when two or more transactions each hold a lock the other needs, causing all of them to wait indefinitely.
What does the CAP theorem state about distributed databases?
Answer: Consistency, Availability, and Partition tolerance cannot all be guaranteed simultaneously
The CAP theorem states that a distributed system can only guarantee two of three properties: Consistency, Availability, and Partition tolerance.