Horton

PROC_IN_ANALYZE stillborn 13 years ago

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Andres Freund <andres@anarazel.de>
Cc: James Coleman <jtc331@gmail.com>, pgsql-hackers <pgsql-hackers@lists.postgresql.org>, simon@2ndquadrant.com
Date: 2020-08-05T23:55:49Z
Lists: pgsql-hackers

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Back in the 8.3 cycle (2007) when the autovacuum launcher/worker split
was done, we annoyed people because it blocked DDL.  That led to an
effort to cancel autovac automatically when that was detected, by Simon
Riggs.
https://postgr.es/m/1191526327.4223.204.camel@ebony.site
https://postgr.es/m/1192129897.4233.433.camel@ebony.site

I was fixated on only cancelling when it was ANALYZE, to avoid losing
any VACUUM work.
https://postgr.es/m/20071025164150.GF23566@alvh.no-ip.org
That turned into some flags for PGPROC to detect whether a process was
ANALYZE, and cancel only those.
https://postgr.es/m/20071024151328.GG6559@alvh.no-ip.org
Commit:
https://postgr.es/m/20071024205536.CB425754229@cvs.postgresql.org
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=745c1b2c2ab

However, I was outvoted, so we do not limit cancellation to analyze.
Patch and discussion: https://postgr.es/m/20071025164150.GF23566@alvh.no-ip.org
Commit:
https://postgr.es/m/20071026204510.AA02E754229@cvs.postgresql.org
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=acac68b2bca

... which means the flag I had added two days earlier has never been
used for anything.  We've carried the flag forward to this day for
almost 13 years, dutifully turning it on and off ... but never checking
it anywhere.

I propose to remove it, as in the attached patch.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Call out vacuum considerations in create index docs

  2. Document concurrent indexes waiting on each other

  3. snapshot scalability: Don't compute global horizons while building snapshots.

  4. Remove PROC_IN_ANALYZE and derived flags

  5. Improve performance of get_actual_variable_range with recently-dead tuples.