On Tue, Oct 8, 2019 at 1:48 AM Peter Geoghegan <p...@bowt.ie> wrote: > > On Mon, Oct 7, 2019 at 12:28 PM Robert Haas <robertmh...@gmail.com> wrote: > > I would say that sucks, because it makes it harder to set > > maintenance_work_mem correctly. Not sure how hard it would be to fix, > > though. > > ginInsertCleanup() may now be the worst piece of code in the entire > tree, so no surprised that it gets this wrong too. > > 2016's commit e2c79e14d99 ripped out the following comment about the > use of maintenance_work_mem by ginInsertCleanup(): > > @@ -821,13 +847,10 @@ ginInsertCleanup(GinState *ginstate, > * Is it time to flush memory to disk? Flush if we are at the end of > * the pending list, or if we have a full row and memory is getting > * full. > - * > - * XXX using up maintenance_work_mem here is probably unreasonably > - * much, since vacuum might already be using that much. > */ > > ISTM that the use of maintenance_work_mem wasn't given that much > thought originally. >
One idea to something better could be to check, if there is a GIN index on a table, then use 1/4 (25% or whatever) of maintenance_work_mem for GIN indexes and 3/4 (75%) of maintenance_work_mem for collection dead tuples. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com