On 2020-Aug-25, Andres Freund wrote: > Hi, > > On 2020-08-26 15:58:14 +1200, Thomas Munro wrote: > > > --12.51%--compactify_tuples > > > PageRepairFragmentation > > > heap2_redo > > > StartupXLOG > > > > I wonder if there is something higher level that could be done to > > reduce the amount of compaction work required in the first place, but > > in the meantime I'm very happy if we can improve the situation so much > > with such a microscopic improvement that might eventually benefit > > other sorting stuff... > > Another approach could be to not perform any sorting during recovery, > instead including enough information in the WAL record to avoid doing a > full blown PageRepairFragmentation during recovery.
Hmm, including the sorted ItemId array in the WAL record might make sense to alleviate the qsort work ... -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
