On Mon, Jan 1, 2018 at 8:56 AM, Martin Moore <martin.moore@xxxxxxxxxxx> wrote: > Can someone shed some light on this and advise how to prevent it reoccurring? You're using v10, which has these two commits: https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=58b25e98106dbe062cec0f3d31d64977bffaa4af https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=9fab40ad32efa4038d19eaed975bb4c1713ccbc0 Unfortunately, per the commit message of the first commit, it doesn't look like the tuple allocator uses any new strategy, at least until this v11 commit: https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=a4ccc1cef5a04cc054af83bc4582a045d5232cb3 My guess is that that would make a noticeable difference, once v11 becomes available. Could you test this yourself by building from the master branch? -- Peter Geoghegan