On Wed, 16 Sep 2020 at 02:10, Jakub Wartak <jakub.war...@tomtom.com> wrote: > BTW: this message "redo done at 0/9749FF70 system usage: CPU: user: 13.46 s, > system: 0.78 s, elapsed: 14.25 s" is priceless addition :)
Thanks a lot for the detailed benchmark results and profiles. That was useful. I've pushed both patches now. I did a bit of a sweep of the comments on the 0001 patch before pushing it. I also did some further performance tests of something other than recovery. I can also report a good performance improvement in VACUUM. Something around the ~25% reduction mark psql -c "drop table if exists t1;" postgres > /dev/null psql -c "create table t1 (a int primary key, b int not null) with (autovacuum_enabled = false, fillfactor = 85);" postgres > /dev/null psql -c "insert into t1 select x,0 from generate_series(1,10000000) x;" postgres > /dev/null psql -c "drop table if exists log_wal;" postgres > /dev/null psql -c "create table log_wal (lsn pg_lsn not null);" postgres > /dev/null psql -c "insert into log_wal values(pg_current_wal_lsn());" postgres > /dev/null pgbench -n -f update.sql -t 60000 -c 200 -j 200 -M prepared postgres psql -c "select 'Used ' || pg_size_pretty(pg_wal_lsn_diff(pg_current_wal_lsn(), lsn)) || ' of WAL' from log_wal limit 1;" postgres psql postgres \timing on VACUUM t1; Fillfactor = 85 patched: Time: 2917.515 ms (00:02.918) Time: 2944.564 ms (00:02.945) Time: 3004.136 ms (00:03.004) master: Time: 4050.355 ms (00:04.050) Time: 4104.999 ms (00:04.105) Time: 4158.285 ms (00:04.158) Fillfactor = 100 Patched: Time: 4245.676 ms (00:04.246) Time: 4251.485 ms (00:04.251) Time: 4247.802 ms (00:04.248) Master: Time: 5459.433 ms (00:05.459) Time: 5917.356 ms (00:05.917) Time: 5430.986 ms (00:05.431) David
