postgresql/src/test
Richard Guo 1132af22cf Fix HAVING-to-WHERE pushdown for simple-CASE form
Commit f76686ce7 added a walker that detects when a HAVING clause uses
a collation that conflicts with the GROUP BY's nondeterministic
collation, keeping such clauses in HAVING.  The walker uses
exprInputCollation() to identify each ancestor's comparison collation,
but missed the simple-CASE case: parse analysis builds each WHEN as
OpExpr(CaseTestExpr op val), where CaseTestExpr is a placeholder for
the arg, while the actual arg expression sits at cexpr->arg, outside
the OpExpr that carries the comparison's inputcollid.  A GROUP Var at
cexpr->arg was therefore visited with the WHEN's inputcollid absent
from the ancestor stack, the conflict went undetected, and the clause
was wrongly pushed to WHERE.

Fix by handling simple CASE explicitly: before walking cexpr->arg,
push every WHEN's inputcollid onto the ancestor stack so a GROUP Var
at the arg is checked against the same collations the WHEN comparisons
would apply.  Then walk the WHEN bodies and defresult under the
unchanged stack, where their own collation contexts are picked up by
the default path.

Back-patch to v18 only; this fix extends the walker added by commit
f76686ce7 and inherits its dependency on the v18 RTE_GROUP mechanism.

Author: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAHg+QDcqPdd=2V0PQ_oNYj50OUeqSqznqFaYtP3RdokLBDXBqw@mail.gmail.com
Backpatch-through: 18
2026-05-08 10:59:13 +09:00
..
authentication Run pgperltidy 2025-06-29 21:14:21 -04:00
examples libpq: Deprecate pg_int64. 2025-03-25 21:40:00 +13:00
icu Update copyright for 2025 2025-01-01 11:21:55 -05:00
isolation Fix handling of updated tuples in the MERGE statement 2026-03-05 19:50:06 +02:00
kerberos Replace deprecated log_connections values in docs and tests 2025-05-22 17:14:54 -04:00
ldap Replace deprecated log_connections values in docs and tests 2025-05-22 17:14:54 -04:00
locale Update copyright for 2025 2025-01-01 11:21:55 -05:00
mb Fix MB regression tests for WAL-logging of hash indexes. 2017-03-15 07:25:36 -04:00
modules test_tidstore: Stabilize regression tests by sorting offsets. 2026-04-29 09:10:07 -07:00
perl More tar portability adjustments. 2026-04-04 14:02:28 +13:00
postmaster Make postmaster 003_start_stop.pl test less flaky 2025-12-17 16:26:26 +02:00
recovery Fix rare instability in recovery TAP test 004_timeline_switch 2026-03-05 10:06:01 +09:00
regress Fix HAVING-to-WHERE pushdown for simple-CASE form 2026-05-08 10:59:13 +09:00
ssl Fix thinko in commit 7d129ba54. 2025-10-20 08:45:57 -04:00
subscription Fix logical replication TAP test to read publisher log correctly. 2026-02-05 00:46:09 +09:00
Makefile Add PG_TEST_EXTRA configure option to the Make builds 2024-11-04 14:09:38 +02:00
meson.build Update copyright for 2025 2025-01-01 11:21:55 -05:00
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