08 - OLTP concurrency Flashcards
1
Q
When do operations conflict?
A
If one writes an object before another reads or writes it
2
Q
What is an S lock?
A
Read / shared lock
3
Q
What is an X log?
A
Write / exclusive log
4
Q
What is an IS lock?
A
Intention Shared lock
5
Q
What is an IX lock?
A
Intention Exclusive Lock
6
Q
S lock compatibility
A
S, IS
7
Q
X lock compatibility
A
Nothing
8
Q
IS lock compatibility
A
S, IS, IX
9
Q
IX log compatibility
A
IS, IX
