postgresql/src/test
Tom Lane e79b276621 Allow indexscans on partial hash indexes with implied quals.
Normally, if a WHERE clause is implied by the predicate of a partial
index, we drop that clause from the set of quals used with the index,
since it's redundant to test it if we're scanning that index.
However, if it's a hash index (or any !amoptionalkey index), this
could result in dropping all available quals for the index's first
key, preventing us from generating an indexscan.

It's fair to question the practical usefulness of this case.  Since
hash only supports equality quals, the situation could only arise
if the index's predicate is "WHERE indexkey = constant", implying
that the index contains only one hash value, which would make hash
a really poor choice of index type.  However, perhaps there are
other !amoptionalkey index AMs out there with which such cases are
more plausible.

To fix, just don't filter the candidate indexquals this way if
the index is !amoptionalkey.  That's a bit hokey because it may
result in testing quals we didn't need to test, but to do it
more accurately we'd have to redundantly identify which candidate
quals are actually usable with the index, something we don't know
at this early stage of planning.  Doesn't seem worth the effort.

Reported-by: Sergei Glukhov <s.glukhov@postgrespro.ru>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/e200bf38-6b45-446a-83fd-48617211feff@postgrespro.ru
Backpatch-through: 14
2025-11-27 13:09:59 -05:00
..
authentication Fix an assortment of typos 2024-05-04 02:33:25 +12:00
examples Update copyright for 2024 2024-01-03 20:49:05 -05:00
icu Address more review comments on commit 2d819a08a1. 2024-03-18 11:58:13 -07:00
isolation Fix Assert failure in EXPLAIN ANALYZE MERGE with a concurrent update. 2025-11-16 22:15:45 +00:00
kerberos Move Kerberos module 2024-04-08 02:49:30 +03:00
ldap Don't clobber test exit code at cleanup in LDAP/Kerberors tests 2024-04-07 20:21:27 +03:00
locale Update copyright for 2024 2024-01-03 20:49:05 -05:00
mb Fix MB regression tests for WAL-logging of hash indexes. 2017-03-15 07:25:36 -04:00
modules Fix bug where we truncated CLOG that was still needed by LISTEN/NOTIFY 2025-11-12 21:01:13 +02:00
perl Fix missing "use Test::More" in Kerberos.pm. 2025-08-18 14:54:59 -04:00
recovery Fix timing-dependent failure in recovery test 004_timeline_switch 2025-11-05 16:48:24 +09:00
regress Allow indexscans on partial hash indexes with implied quals. 2025-11-27 13:09:59 -05:00
ssl Fix thinko in commit 7d129ba54. 2025-10-20 08:45:57 -04:00
subscription Fix self-deadlock during DROP SUBSCRIPTION. 2025-08-19 05:06:37 +00:00
Makefile Refactor PG_TEST_EXTRA logic in autoconf build 2022-09-20 11:24:16 -07:00
meson.build Move libpq encryption negotiation tests 2024-04-12 19:52:37 +03:00
README Remove the option to build thread_test.c outside configure. 2020-10-21 12:08:48 -04:00

PostgreSQL tests
================

This directory contains a variety of test infrastructure as well as some of the
tests in PostgreSQL. Not all tests are here -- in particular, there are more in
individual contrib/ modules and in src/bin.

Not all these tests get run by "make check". Check src/test/Makefile to see
which tests get run automatically.

authentication/
  Tests for authentication (but see also below)

examples/
  Demonstration programs for libpq that double as regression tests via
  "make check"

isolation/
  Tests for concurrent behavior at the SQL level

kerberos/
  Tests for Kerberos/GSSAPI authentication and encryption

ldap/
  Tests for LDAP-based authentication

locale/
  Sanity checks for locale data, encodings, etc

mb/
  Tests for multibyte encoding (UTF-8) support

modules/
  Extensions used only or mainly for test purposes, generally not suitable
  for installing in production databases

perl/
  Infrastructure for Perl-based TAP tests

recovery/
  Test suite for recovery and replication

regress/
  PostgreSQL's main regression test suite, pg_regress

ssl/
  Tests to exercise and verify SSL certificate handling

subscription/
  Tests for logical replication