Transaction Mgmt

Data Base Modeling

15 cards·by Brutusdeacon

What is a transaction?

A unit of work

What are the 3 phases of processing queries?

Parsiing, Execution, Fetching

What does good database performance start with?

Good database design

What is atomic?

The smallest unit of work

What is a deadlock?

Two people each have a piece of work the other needs and won't give it up - so they are deadlocked

What is a lost update problem?

two concurrent transactions update same data element and one is lost because the other overwrites it

What is a lost update problem?

two concurrent transactions update same data element and one is lost because the other overwrites it

What is a lost update problem?

two concurrent transactions update same data element and one is lost because the other overwrites it

what is a row level lock

allows concurrent transactions to access different rows of same table even if rows are located on same page

What does a field level lock do?

allows concurrent transactions to access same row

What are the two states of a binary lock?

Locked or unlocked

What are the phases of the locking protocol?

grow - lock shrink

What is database performance tuning?

Refers to activities to ensure query is processed in minimum amount of time

What is SQL performance tuning

refers to activities to ensure query is processed in minimum amount of time

what is the importance of indexes?

they are crucial in the process that speeds up data access