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Michael Paquier dd9ac7d5d8 Revert "Skip redundant anti-wraparound vacuums"
This reverts commit 2aa6e33, that added a fast path to skip
anti-wraparound and non-aggressive autovacuum jobs (these have no sense
as anti-wraparound implies aggressive).  With a cluster using a high
amount of relations with a portion of them being heavily updated, this
could cause autovacuum to lock down, with autovacuum workers attempting
repeatedly those jobs on the same relations for the same database, that
just kept being skipped.  This lock down can be solved with a manual
VACUUM FREEZE.

Justin King has reported one environment where the issue happened, and
Julien Rouhaud and I have been able to reproduce it in a second
environment.  With a very aggressive autovacuum_freeze_max_age,
triggering those jobs with pgbench is a matter of minutes, and hitting
the lock down is a lot harder (my local tests failed to do that).

Note that anti-wraparound and non-aggressive jobs can only be triggered
on a subset of shared catalogs:
- pg_auth_members
- pg_authid
- pg_database
- pg_replication_origin
- pg_shseclabel
- pg_subscription
- pg_tablespace
While the lock down was possible down to v12, the root cause of those
jobs is a much older issue, which needs more analysis.

Bonus thanks to Andres Freund for the discussion.

Reported-by: Justin King
Discussion: https://postgr.es/m/CAE39h22zPLrkH17GrkDgAYL3kbjvySYD1io+rtnAUFnaJJVS4g@mail.gmail.com
Backpatch-through: 12
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src Revert "Skip redundant anti-wraparound vacuums" 2020-03-31 08:27:47 +09:00
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PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download/

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.