Andres Freund 817f9f9a8a Fix bugs in vacuum of shared rels, by keeping their relcache entries current. ... When vacuum processes a relation it uses the corresponding relcache entry's relfrozenxid / relminmxid as a cutoff for when to remove tuples etc. Unfortunately for nailed relations (i.e. critical system catalogs) bugs could frequently lead to the corresponding relcache entry being stale. This set of bugs could cause actual data corruption as vacuum would potentially not remove the correct row versions, potentially reviving them at a later point. After 699bf7d05c some corruptions in this vein were prevented, but the additional error checks could also trigger spuriously. Examples of such errors are: ERROR: found xmin ... from before relfrozenxid ... and ERROR: found multixact ... from before relminmxid ... To be caused by this bug the errors have to occur on system catalog tables. The two bugs are: 1) Invalidations for nailed relations were ignored, based on the theory that the relcache entry for such tables doesn't change. Which is largely true, except for fields like relfrozenxid etc. This means that changes to relations vacuumed in other sessions weren't picked up by already existing sessions. Luckily autovacuum doesn't have particularly longrunning sessions. 2) For shared *and* nailed relations, the shared relcache init file was never invalidated while running. That means that for such tables (e.g. pg_authid, pg_database) it's not just already existing sessions that are affected, but even new connections are as well. That explains why the reports usually were about pg_authid et. al. To fix 1), revalidate the rd_rel portion of a relcache entry when invalid. This implies a bit of extra complexity to deal with bootstrapping, but it's not too bad. The fix for 2) is simpler, simply always remove both the shared and local init files. Author: Andres Freund Reviewed-By: Alvaro Herrera Discussion: https://postgr.es/m/20180525203736.crkbg36muzxrjj5e@alap3.anarazel.de https://postgr.es/m/CAMa1XUhKSJd98JW4o9StWPrfS=11bPgG+_GDMxe25TvUY4Sugg@mail.gmail.com https://postgr.es/m/CAKMFJucqbuoDRfxPDX39WhA3vJyxweRg_zDVXzncr6+5wOguWA@mail.gmail.com https://postgr.es/m/CAGewt-ujGpMLQ09gXcUFMZaZsGJC98VXHEFbF-tpPB0fB13K+A@mail.gmail.com Backpatch: 9.3-		2018-06-12 11:13:22 -07:00
..
backend	Fix bugs in vacuum of shared rels, by keeping their relcache entries current.	2018-06-12 11:13:22 -07:00
bin	Improve inefficient regexes in vacuumdb TAP test.	2018-05-08 20:17:43 -04:00
common	Enlarge find_other_exec's meager fgets buffer	2018-04-19 10:45:15 -03:00
include	Support platforms where strtoll/strtoull are spelled __strtoll/__strtoull.	2018-05-19 14:22:19 -04:00
interfaces	printf("%lf") is not portable, so omit the "l".	2018-05-20 11:40:54 -04:00
makefiles	Always use -fPIC, not -fpic, when building shared libraries with gcc.	2017-06-01 13:32:56 -04:00
pl	Fix misidentification of SQL statement type in plpgsql's exec_stmt_execsql.	2018-05-25 14:31:07 -04:00
port	Fix simple_prompt() to disable echo on Windows when stdin != terminal.	2018-05-23 19:04:34 -04:00
template	AIX: Test the -qlonglong option before use.	2015-07-17 03:01:35 -04:00
test	Properly schema-qualify additional object types in getObjectDescription().	2018-05-24 12:07:41 -04:00
timezone	Update time zone data files to tzdata release 2018e.	2018-05-09 13:56:00 -04:00
tools	Clear severity 5 perlcritic warnings from vcregress.pl	2018-05-06 07:40:04 -04:00
tutorial	pgindent run for 9.4	2014-05-06 12:12:18 -04:00
.gitignore
bcc32.mak
DEVELOPERS
Makefile	Install TAP test infrastructure so it's available for extension testing.	2016-09-23 15:50:00 -04:00
Makefile.global.in	PL/Perl portability fix: absorb relevant -D switches from Perl.	2017-07-31 12:38:35 -04:00
Makefile.shlib	Fix make rules that generate multiple output files.	2018-03-23 13:45:38 -04:00
nls-global.mk	nls-global.mk: search build dir for source files, too	2016-06-07 18:55:18 -04:00
win32.mak