On 2026-Jul-09, Heikki Linnakangas wrote:
> Why is the autovacuum launcher not an aux process? I guess it's because it
> needs to acquire a heavy-weight lock in order to read the list of databases.
Because it scans pg_database.
commit 00e6a16d01683762c2f34eb4909fc739093ab3bf
Author: Tom Lane <tgl@sss.pgh.pa.us> []
AuthorDate: Mon Aug 31 19:41:00 2009 +0000
CommitDate: Mon Aug 31 19:41:00 2009 +0000
Change the autovacuum launcher to read pg_database directly, rather than
via the "flat files" facility. This requires making it enough like a backend
to be able to run transactions; it's no longer an "auxiliary process" but
more like the autovacuum worker processes. Also, its signal handling has
to be brought into line with backends/workers. In particular, since it
now has to handle procsignal.c processing, the special autovac-launcher-only
signal conditions are moved to SIGUSR2.
Alvaro, with some cleanup from Tom
--
Álvaro Herrera 48°01'N 7°57'E — https://www.EnterpriseDB.com/
"If you want to have good ideas, you must have many ideas. Most of them
will be wrong, and what you have to learn is which ones to throw away."
(Linus Pauling)
