Questions tagged [two-phase-locking]
2 questions
1
vote
2 answers
Does two phase locking actually prevent lost updates?
Two phase locking is claimed to be a solution for ensuring serial execution. However, I'm not sure how it adequately solves the lost update problem during a read-modify-write cycle. I may be overlooking / misunderstanding the locking mechanism…
linstantnoodles
- 4,350
- 1
- 22
- 24
0
votes
0 answers
How many message delays does two-phase locking requires to commit a txn in normal case?
I read some tutorials on two-phase commit
https://www.cs.cmu.edu/~dga/15-440/F10/lectures/Concurrency-Control.pdf [Slide 27]
It seems that, when there are multiple shards [participants], it needs 4 message delays for the coordinator to commit the…
steamgjk
- 11
- 1