Fundamentals of Databases Flashcards
How do I get to 1NF?
No non-atomic values
How do I get from 1NF to 2NF?
No partial key dependences
How to I get from 2NF to 3NF?
No transitive dependencies (everything is only dependent on the primary key)
Why do we normalise databases?
So they can run optimally without compromising the integrity of the data
What problem occurs when different users attempt to access the same field in client server database at the same time?
Concurrent access
How do we manage concurrent access?
- Record locks
- Serialisation
- Timestamp ordering
- Commitment ordering
What are record locks?
Ensures that only one user can modify a specific record at a time - prevents inconsistencies that could occur if users make different changes simultaneously.
What is timestamp ordering?
A concurrency control technique in database systems that uses timestamps to determine the order transactions are executed
