Re: Increase value of OUTER_VAR
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Andrey Lepikhov <a.lepikhov@postgrespro.ru>,
Julien Rouhaud <rjuju123@gmail.com>,
Amit Langote <amitlangote09@gmail.com>,
David Rowley <dgrowleyml@gmail.com>,
PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-03-04T15:16:49Z
Lists: pgsql-hackers
Tomas Vondra <tomas.vondra@enterprisedb.com> writes: > IMO just bumping up the constants from ~65k to 1M is a net loss, for > most users. We add this to bitmapsets, which means we're using ~8kB with > the current values, but this jumps to 128kB with this higher value. This > also means bms_next_member etc. have to walk much more memory, which is > bound to have some performance impact for everyone. Hmm, do we really have any places that include OUTER_VAR etc in bitmapsets? They shouldn't appear in relid sets, for sure. I agree though that if they did, this would have bad performance consequences. I still think the negative-special-values approach is better. If there are any places that that would break, we'd find out about it in short order, rather than having a silent performance lossage. regards, tom lane
Commits
-
Remove arbitrary 64K-or-so limit on rangetable size.
- e3ec3c00d85b 15.0 landed
-
More cleanups of the include files
- 105409746499 7.1.1 cited