Mark Kirkwood <[EMAIL PROTECTED]> writes: > Tom Lane wrote: >> Sounds like a recipe for ensuring it never will be tested. What's >> needed here is some actual tests, not preparation...
> Does the OP have a test scenario that those of us with appropriate OS's > could try? Come to think of it, what are the appropriate OS's? (I see > NetBSD mentioned so I suppose all the *BSDs, but what others?). The test run by the OP was just pgbench, which is probably not the greatest scenario for showing the benefits of this patch, but at least it's neutral ground. You need a situation in which the kernel is under memory stress, else early free of disk cache buffers isn't going to make any difference whatever --- so choose a pgbench scale factor that makes the database noticeably larger than the test machine's RAM. Other than that, follow the usual guidelines for producing trustworthy pgbench numbers: number of clients smaller than scale factor, number of transactions per client at least 1000 or so (to eliminate startup transients), repeat test a couple times to make sure numbers are reproducible. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings