postgresql/src/test
Tom Lane 55dc86eca7 Fix pull_varnos' miscomputation of relids set for a PlaceHolderVar.
Previously, pull_varnos() took the relids of a PlaceHolderVar as being
equal to the relids in its contents, but that fails to account for the
possibility that we have to postpone evaluation of the PHV due to outer
joins.  This could result in a malformed plan.  The known cases end up
triggering the "failed to assign all NestLoopParams to plan nodes"
sanity check in createplan.c, but other symptoms may be possible.

The right value to use is the join level we actually intend to evaluate
the PHV at.  We can get that from the ph_eval_at field of the associated
PlaceHolderInfo.  However, there are some places that call pull_varnos()
before the PlaceHolderInfos have been created; in that case, fall back
to the conservative assumption that the PHV will be evaluated at its
syntactic level.  (In principle this might result in missing some legal
optimization, but I'm not aware of any cases where it's an issue in
practice.)  Things are also a bit ticklish for calls occurring during
deconstruct_jointree(), but AFAICS the ph_eval_at fields should have
reached their final values by the time we need them.

The main problem in making this work is that pull_varnos() has no
way to get at the PlaceHolderInfos.  We can fix that easily, if a
bit tediously, in HEAD by passing it the planner "root" pointer.
In the back branches that'd cause an unacceptable API/ABI break for
extensions, so leave the existing entry points alone and add new ones
with the additional parameter.  (If an old entry point is called and
encounters a PHV, it'll fall back to using the syntactic level,
again possibly missing some valid optimization.)

Back-patch to v12.  The computation is surely also wrong before that,
but it appears that we cannot reach a bad plan thanks to join order
restrictions imposed on the subquery that the PlaceHolderVar came from.
The error only became reachable when commit 4be058fe9 allowed trivial
subqueries to be collapsed out completely, eliminating their join order
restrictions.

Per report from Stephan Springl.

Discussion: https://postgr.es/m/171041.1610849523@sss.pgh.pa.us
2021-01-21 15:37:23 -05:00
..
authentication Update copyright for 2021 2021-01-02 13:06:25 -05:00
examples Update copyright for 2021 2021-01-02 13:06:25 -05:00
isolation Allow pg_regress.c wrappers to postprocess test result files. 2021-01-11 13:43:19 -05:00
kerberos Update copyright for 2021 2021-01-02 13:06:25 -05:00
ldap Update copyright for 2021 2021-01-02 13:06:25 -05:00
locale Clean up after tests in src/test/locale/. 2020-11-28 16:08:36 -05:00
mb Fix MB regression tests for WAL-logging of hash indexes. 2017-03-15 07:25:36 -04:00
modules Add missing array-enlargement logic to test_regex.c. 2021-01-17 12:53:48 -05:00
perl Update copyright for 2021 2021-01-02 13:06:25 -05:00
recovery Stabilize timeline switch regression test. 2021-01-14 23:55:33 +09:00
regress Fix pull_varnos' miscomputation of relids set for a PlaceHolderVar. 2021-01-21 15:37:23 -05:00
ssl Update copyright for 2021 2021-01-02 13:06:25 -05:00
subscription Update copyright for 2021 2021-01-02 13:06:25 -05:00
Makefile remove missing reference to crypto test from patch 978f869b99 2020-12-25 15:13:25 -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