On Wed, Feb 24, 2016 at 9:17 AM, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: >> Well, turns out there's a quite significant difference, actually. The >> index sizes I get (quite stable after multiple runs): >> >> 9.5 : 2428 MB >> 9.6 + alone cleanup : 730 MB >> 9.6 + pending lock : 488 MB >> >> So that's quite a significant difference, I guess. The load duration for >> each version look like this: >> >> 9.5 : 1415 seconds >> 9.6 + alone cleanup : 1310 seconds >> 9.6 + pending lock : 1380 seconds >> >> I'd say I'm happy with sacrificing ~5% of time in exchange for ~35% >> reduction of index size. >> >> The size of the index on 9.5 after VACUUM FULL (so pretty much the >> smallest index possible) is 440MB, which suggests the "pending lock" >> patch does a quite good job. >> >> The gin_metapage_info at the end of one of the runs (pretty much all the >> runs look exactly the same) looks like this: >> >> pending lock alone cleanup 9.5 >> -------------------------------------------------------- >> pending_head 2 2 310460 >> pending_tail 338 345 310806 >> tail_free_size 812 812 812 >> n_pending_pages 330 339 347 >> n_pending_tuples 1003 1037 1059 >> n_total_pages 2 2 2 >> n_entry_pages 1 1 1 >> n_data_pages 0 0 0 >> n_entries 0 0 0 >> version 2 2 2 >> >> So almost no difference, except for the pending_* attributes, and even >> in that case the values are only different for 9.5 branch. Not sure what >> conclusion to draw from this - maybe it's necessary to collect the >> function input while the load is running (but that'd be tricky to >> process, I guess). > > Are we going to anything about this? While the bug is present in 9.5 (and > possibly other versions), fixing it before 9.6 gets out seems important > because reproducing it there is rather trivial (while I've been unable to > reproduce it on 9.5).
I'm not going to promise to commit anything here, because GIN is not usually my area, but could you provide a link to the email that contains the patch you think should be committed? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
