postgresql/contrib
Tom Lane 09c9ae8f6d Avoid resource leaks when a dblink connection fails.
If we hit out-of-memory between creating the PGconn and inserting
it into dblink's hashtable, we'd lose track of the PGconn, which
is quite bad since it represents a live connection to a remote DB.
Fix by rearranging things so that we create the hashtable entry
first.

Also reduce the number of states we have to deal with by getting rid
of the separately-allocated remoteConn object, instead allocating it
in-line in the hashtable entries.  (That incidentally removes a
session-lifespan memory leak observed in the regression tests.)

There is an apparently-irreducible remaining OOM hazard, which
is that if the connection fails at the libpq level (ie it's
CONNECTION_BAD) then we have to pstrdup the PGconn's error message
before we can release it, and theoretically that could fail.  However,
in such cases we're only leaking memory not a live remote connection,
so I'm not convinced that it's worth sweating over.

This is a pretty low-probability failure mode of course, but losing
a live connection seems bad enough to justify back-patching.

Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Discussion: https://postgr.es/m/1346940.1748381911@sss.pgh.pa.us
Backpatch-through: 13
2025-05-29 10:39:55 -04:00
..
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 Replace durable_rename_excl() by durable_rename(), take two 2024-12-20 09:11:03 +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 Avoid resource leaks when a dblink connection fails. 2025-05-29 10:39:55 -04:00
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 Make contrib modules' installation scripts more secure. 2020-08-10 10:44:42 -04:00
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 Make contrib modules' installation scripts more secure. 2020-08-10 10:44:42 -04:00
hstore_plpython In hstore_plpython, avoid crashing when return value isn't a mapping. 2023-04-27 11:55:06 -04:00
intagg Make contrib modules' installation scripts more secure. 2020-08-10 10:44:42 -04:00
intarray Fix GIN's shimTriConsistentFn to not corrupt its input. 2025-04-12 12:27:46 -04:00
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 Repair incorrect handling of AfterTriggerSharedData.ats_modifiedcols. 2025-01-22 11:58:20 -05:00
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 Be more wary of corrupt data in pageinspect's heap_page_items(). 2025-04-19 16:37:42 -04:00
passwordcheck Remove non-functional code for unloading loadable modules. 2022-05-11 15:30:30 -04:00
pg_buffercache Remove support for upgrading extensions from "unpackaged" state. 2020-02-19 16:59:14 -05:00
pg_freespacemap Prevent assertion failure in contrib/pg_freespacemap. 2025-03-27 13:20:23 -04:00
pg_prewarm Add a new shmem_request_hook hook. 2022-05-13 09:31:06 -04:00
pg_stat_statements pg_stat_statements: Fix parameter number gaps in normalized queries 2025-05-29 11:26:29 +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 Restore smgrtruncate() prototype in back-branches. 2025-01-08 10:47:43 +13:00
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 Handle default NULL insertion a little better. 2025-01-29 15:31:55 -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 Remove contrib/start-scripts/osx/. 2017-11-17 12:53:20 -05:00
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 xmin advancement during fast_forward decoding. 2025-04-28 10:56:24 +05:30
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 Respect TEMP_CONFIG when pg_regress_check and friends are called 2016-02-27 12:28:21 -05:00
Makefile Add contrib/pg_walinspect. 2022-04-08 00:26:44 -07:00
README Rename 'gmake' to 'make' in docs and recommended commands 2014-02-12 17:29:19 -05:00

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.