> On Aug 2, 2024, at 2:29 PM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > > Scott Ribe <scott_ribe@xxxxxxxxxxxxxxxx> writes: >> I'd like to measure both the amount of WAL created by a long series of data modifications and the compressed size of the generated WAL files. >> I suppose I need to set wal_keep_size high, and pay attention to segment numbers to make sure it was high enough. Then I can look at segments created while the commands were running. > >> But question: can I simply delete all WAL after a clean shutdown? > > As a general rule, never do that manually --- the risk/reward ratio is > unattractive. A checkpoint will release all safely-releasable WAL. > You can checkpoint via a shutdown if you insist, but a plain > CHECKPOINT command should be enough. Oh, I thought at a checkpoint it would keep around some minimum, wal_keep_size, or wal_min_size. But I suppose I could set those to 0 if needed. Anyway, this would be a database solely for the purpose of running these tests, starting empty, so risk is not a factor unless I keep corrupting it between test stages ;-)
