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That's not how postgres works. You're talking about 2PL. Serializable isolation level in postgres does have something called predicate locks, but those are actu
by petergeoghegan 9y ago
That's not how postgres works. You're talking about 2PL. Serializable isolation level in postgres does have something called predicate locks, but those are actually quite a different thing.
- skyde 9y agoNo I was talking exactly about Predicate Locking. They detect writes which conflict with earlier reads I dont think this could be called 2PL because it's only used to detect conflict. Correctness requires that any insert into an index generate a rw-conflict with a concurrent serializable transaction if, after that insert, re-execution of any index scan of the other transaction would access the heap for a row not accessed during the previous execution.