postgresql/contrib
Michael Paquier 1df1e1e787 Fix invalidation of local pgstats references for entry reinitialization
818119afcc has introduced the "generation" concept in pgstats entries,
incremented a counter when a pgstats entry is reinitialized, but it did
not count on the fact that backends still holding local references to
such entries need to be refreshed if the cache age is outdated.  The
previous logic only updated local references when an entry was dropped,
but it needs also to consider entries that are reinitialized.

This matters for replication slot stats (as well as custom pgstats kinds
in 18~), where concurrent drops and creates of a slot could cause
incorrect stats to be locally referenced.  This would lead to an
assertion failure at shutdown when writing out the stats file, as the
backend holding an outdated local reference would not be able to drop
during its shutdown sequence the stats entry that should be dropped, as
the last process holding a reference to the stats entry.  The
checkpointer was then complaining about such an entry late in the
shutdown sequence, after the shutdown checkpoint is finished with the
control file updated, causing the stats file to not be generated.  In
non-assert builds, the entry would just be skipped with the stats file
written.

Note that only logical replication slots use statistics.

A test case based on TAP is added to test_decoding, where a persistent
connection peeking at a slot's data is kept with concurrent drops and
creates of the same slot.  This is based on the isolation test case that
Anton has sent.  As it requires a node shutdown with a check to make
sure that the stats file is written with this specific sequence of
events, TAP is used instead.

Reported-by: Anton A. Melnikov
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/56bf8ff9-dd8c-47b2-872a-748ede82af99@postgrespro.ru
Backpatch-through: 15
2024-12-09 10:46:10 +09:00
..
adminpack Use has_privs_for_roles for predefined role checks 2022-03-28 15:10:04 -04:00
amcheck Backport BackgroundPsql perl test module 2024-06-27 19:01:13 +03:00
auth_delay Disallow setting bogus GUCs within an extension's reserved namespace. 2022-02-21 14:10:43 -05:00
auto_explain Make new auto_explain test safe for log_error_verbosity = verbose. 2022-07-31 12:29:44 -04:00
basebackup_to_shell basebackup_to_shell: Check for a NULL return from OpenPipeStream. 2023-04-12 11:51:09 -04:00
basic_archive Fix calculation related to temporary WAL segment name in basic_archive 2022-10-17 11:40:19 +09:00
bloom Count contrib/bloom index scans in pgstat view. 2024-11-12 20:57:39 -05:00
bool_plperl Fix broken ruleutils support for function TRANSFORM clauses. 2021-01-25 13:03:43 -05:00
btree_gin btree_gin: Fix calculation of leftmost interval value. 2023-10-29 11:14:35 +00:00
btree_gist Pre-beta mechanical code beautification. 2022-05-12 15:17:30 -04:00
citext Skip citext_utf8 test on Windows. 2024-08-02 10:13:16 +12:00
cube Indent C code in flex and bison files 2022-05-13 07:17:29 +02:00
dblink Rename SetSingleFuncCall() to InitMaterializedSRF() 2022-10-18 10:22:40 +09:00
dict_int Update copyright for 2022 2022-01-07 19:04:57 -05:00
dict_xsyn Update copyright for 2022 2022-01-07 19:04:57 -05:00
earthdistance
file_fdw Add header matching mode to COPY FROM 2022-03-30 09:02:31 +02:00
fuzzystrmatch Ensure Soundex difference() function handles empty input sanely. 2023-05-16 10:53:42 -04:00
hstore hstore: Tighten key/value parsing check for whitespaces 2023-06-12 09:14:13 +09:00
hstore_plperl
hstore_plpython In hstore_plpython, avoid crashing when return value isn't a mapping. 2023-04-27 11:55:06 -04:00
intagg
intarray Fix integer-overflow problem in intarray's g_int_decompress(). 2024-01-07 15:19:50 -05:00
isn Update copyright for 2022 2022-01-07 19:04:57 -05:00
jsonb_plperl Expose internal function for converting int64 to numeric 2020-09-09 20:16:28 +02:00
jsonb_plpython plpython: Code cleanup related to removal of Python 2 support. 2022-03-07 18:30:28 -08:00
lo
ltree Validate ltree siglen GiST option to be int-aligned 2023-04-23 14:30:51 +03:00
ltree_plpython plpython: Code cleanup related to removal of Python 2 support. 2022-03-07 18:30:28 -08:00
oid2name Improve frontend error logging style. 2022-04-08 14:55:14 -04:00
old_snapshot Update copyright for 2022 2022-01-07 19:04:57 -05:00
pageinspect Fix contrib/pageinspect's test for sequences. 2024-09-13 10:16:40 -05:00
passwordcheck Remove non-functional code for unloading loadable modules. 2022-05-11 15:30:30 -04:00
pg_buffercache
pg_freespacemap Avoid instabilities with the regression tests of pg_freespacemap 2022-03-29 13:52:49 +09:00
pg_prewarm Add a new shmem_request_hook hook. 2022-05-13 09:31:06 -04:00
pg_stat_statements pg_stat_statements: Fix second comment related to entry resets 2023-06-29 09:17:30 +09:00
pg_surgery Remove xloginsert.h from xlog.h 2022-01-30 12:25:24 -03:00
pg_trgm Fix arrays comparison in CompareOpclassOptions() 2024-11-12 01:54:30 +02:00
pg_visibility Remove xloginsert.h from xlog.h 2022-01-30 12:25:24 -03:00
pg_walinspect Limit memory usage of pg_walinspect functions. 2023-02-20 11:29:31 -08:00
pgcrypto pgcrypto: Fix check for buffer size 2024-01-30 11:15:46 +01:00
pgrowlocks Adjust the order of the prechecks in pgrowlocks() 2023-10-31 16:43:01 +13:00
pgstattuple Reintroduce support for sequences in pgstattuple and pageinspect. 2024-09-12 16:31:29 -05:00
postgres_fdw Fix Y2038 issues with MyStartTime. 2024-10-07 13:51:03 -05:00
seg Replace last PushOverrideSearchPath() call with set_config_option(). 2023-05-08 06:14:11 -07:00
sepgsql Adjust sepgsql expected output for 681d9e462 et al. 2023-05-08 11:24:47 -04:00
spi Remove extraneous blank lines before block-closing braces 2022-04-13 19:16:02 +02:00
sslinfo contrib/sslinfo needs a fix too to make hamerkop happy. 2021-11-07 11:33:53 -05:00
start-scripts
tablefunc Remove all traces of tuplestore_donestoring() in the C code 2022-02-17 09:52:02 +09:00
tcn Update copyright for 2022 2022-01-07 19:04:57 -05:00
test_decoding Fix invalidation of local pgstats references for entry reinitialization 2024-12-09 10:46:10 +09:00
tsm_system_rows Update copyright for 2022 2022-01-07 19:04:57 -05:00
tsm_system_time Update copyright for 2022 2022-01-07 19:04:57 -05:00
unaccent unaccent: Tweak value of PYTHON when building without Python support 2023-09-27 14:41:21 +09:00
uuid-ossp Reject bogus output from uuid_create(3). 2022-09-09 12:41:36 -04:00
vacuumlo Improve frontend error logging style. 2022-04-08 14:55:14 -04:00
xml2 Replace usages of xmlXPathCompile() with xmlXPathCtxtCompile(). 2024-09-15 13:33:09 -04:00
contrib-global.mk
Makefile Add contrib/pg_walinspect. 2022-04-08 00:26:44 -07:00
README

The PostgreSQL contrib tree
---------------------------

This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree.  This does not preclude their
usefulness.

User documentation for each module appears in the main SGML
documentation.

When building from the source distribution, these modules are not
built automatically, unless you build the "world" target.  You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.

Some directories supply new user-defined functions, operators, or
types.  To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command.  In a fresh database,
you can simply do

    CREATE EXTENSION module_name;

See the PostgreSQL documentation for more information about this
procedure.