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Can you elaborate? The Postgres documentation leads me to believe this would work fine with the default (READ COMMITTED) isolation level. If multiple transact
by Merad 5y ago
Can you elaborate? The Postgres documentation leads me to believe this would work fine with the default (READ COMMITTED) isolation level. If multiple transactions attempt to modify the same row (incrementing the counter) they're forced to line up until previous updates to that row have been committed or rolled back, hence the risk of lock contention, but each transaction should consistent view of the counter.
- stubish 5y agoYes, I think you are right. The update locks the row containing the last id, and concurrent transactions block if they too need to grab the lock. (so performance wise, a sequence is still better due to less locking, but if you can't have holes it seems fine)