Antonin Houska <[email protected]>: > Do you mean the race related to TransactionIdIsInProgress()? Not sure I > understand, as you suggested above that you no longer need the function.
The "lightweight" approaches I see so far: * XactLockTableWait before replay + SnapshotSelf(GetLatestSnapshot?) * SnapshotDirty + retry logic * SnapshotBelieveEverythingCommitted + modification of HeapTupleSatisfiesUpdate (because it called by heap_update and looks into TransactionIdIsInProgress) > It does not really worry me. The pg_squeeze extension is not MVCC-safe and I > remember there were only 1 or 2 related complaints throughout its > existence. (pg_repack isn't MVCC-safe as well, but I don't keep track of its > issues.) But pg_squeeze and pg_repack are extensions. If we are moving that mechanics into core I'd expect some improvements over pg_squeeze. MVCC-safety of REINDEX CONCURRENTLY makes it possible to run it on a regular basis as some kind of background job. It would be nice to have something like this for the heap. I agree the initial approach is too invasive, complex and performance-heavy to push it forward now. But, any of "lightweight" feels like a good candidate to be shipped with the feature itself - relatively easy and non-invasive. Best regards, Mikhail.
