On Wed, Jul 3, 2019 at 11:42:49AM -0400, Robert Haas wrote: > On Wed, Jul 3, 2019 at 11:24 AM Tomas Vondra > <tomas.von...@2ndquadrant.com> wrote: > > Maybe. And it would probably work for the systems I used for benchmarks. > > > > It however assumes two things: (a) the storage system actually has > > spindles and (b) you know how many spindles there are. Which is becoming > > less and less safe these days - flash storage becomes pretty common, and > > even when there are spindles they are often hidden behind the veil of > > virtualization in a SAN, or something. > > Yeah, that's true. > > > I wonder if we might provide something like pg_test_prefetch which would > > measure performance with different values, similarly to pg_test_fsync. > > That's not a bad idea, but I'm not sure if the results that we got in > a synthetic test - presumably unloaded - would be a good guide to what > to use in a production situation. Maybe it would; I'm just not sure.
I think it would be better than what we have now. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription +
