Tom Lane <tgl@xxxxxxxxxxxxx> writes: > That surprises me too --- can you provide details on the test case so > other people can reproduce it? AFAIR the only performance difference > between SERIALIZABLE and READ COMMITTED is the frequency with which > transaction status snapshots are taken; your report suggests you were > spending 30% of the time in GetSnapshotData, which is a lot higher than > I've ever seen in a profile. Perhaps it reduced the amount of i/o concurrent vacuums were doing? -- greg
