Michael Lewis <mlewis@xxxxxxxxxxx> writes: >> A transaction started with the first statement will not take any SI locks, >> nor will it ever receive a serialization error. > What is the meaning of SI? Anything you are aware of in source code or a > blog post that discusses this? There's src/backend/storage/lmgr/README-SSI, which might or might not be the level of detail you are looking for. regards, tom lane