On 10/6/21, 12:13 AM, "Masahiko Sawada" <sawada.m...@gmail.com> wrote: > A customer reported that during parallel index vacuum, the oldest xmin > doesn't advance. Normally, the calculation of oldest xmin > (ComputeXidHorizons()) ignores xmin/xid of processes having > PROC_IN_VACUUM flag in MyProc->statusFlags. But since parallel vacuum > workers don’t set their statusFlags, the xmin of the parallel vacuum > worker is considered to calculate the oldest xmin. This issue happens > from PG13 where the parallel vacuum was introduced. I think it's a > bug.
+1 > To fix it, I thought that we change the create index code and the > vacuum code so that the individual parallel worker sets its status > flags according to the leader’s one. But ISTM it’d be better to copy > the leader’s status flags to workers in ParallelWorkerMain(). I've > attached a patch for HEAD. The patch seems reasonable to me. Nathan
