postgresql

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History

Tom Lane 976e5844ef Fix improper uses of canonicalize_qual(). One of the things canonicalize_qual() does is to remove constant-NULL subexpressions of top-level AND/OR clauses. It does that on the assumption that what it's given is a top-level WHERE clause, so that NULL can be treated like FALSE. Although this is documented down inside a subroutine of canonicalize_qual(), it wasn't mentioned in the documentation of that function itself, and some callers hadn't gotten that memo. Notably, commit `d007a9505` caused get_relation_constraints() to apply canonicalize_qual() to CHECK constraints. That allowed constraint exclusion to misoptimize situations in which a CHECK constraint had a provably-NULL subclause, as seen in the regression test case added here, in which a child table that should be scanned is not. (Although this thinko is ancient, the test case doesn't fail before 9.2, for reasons I've not bothered to track down in detail. There may be related cases that do fail before that.) More recently, commit `f0e44751d` added an independent bug by applying canonicalize_qual() to index expressions, which is even sillier since those might not even be boolean. If they are, though, I think this could lead to making incorrect index entries for affected index expressions in v10. I haven't attempted to prove that though. To fix, add an "is_check" parameter to canonicalize_qual() to specify whether it should assume WHERE or CHECK semantics, and make it perform NULL-elimination accordingly. Adjust the callers to apply the right semantics, or remove the call entirely in cases where it's not known that the expression has one or the other semantics. I also removed the call in some cases involving partition expressions, where it should be a no-op because such expressions should be canonical already ... and was a no-op, independently of whether it could in principle have done something, because it was being handed the qual in implicit-AND format which isn't what it expects. In HEAD, add an Assert to catch that type of mistake in future. This represents an API break for external callers of canonicalize_qual(). While that's intentional in HEAD to make such callers think about which case applies to them, it seems like something we probably wouldn't be thanked for in released branches. Hence, in released branches, the extra parameter is added to a new function canonicalize_qual_ext(), and canonicalize_qual() is a wrapper that retains its old behavior. Patch by me with suggestions from Dean Rasheed. Back-patch to all supported branches. Discussion: https://postgr.es/m/24475.1520635069@sss.pgh.pa.us		2018-03-11 18:10:42 -04:00
..
examples	Document security implications of search_path and the public schema.	2018-02-26 07:39:48 -08:00
isolation	Remove restriction on SQL block length in isolationtester scanner.	2018-02-28 16:57:37 -05:00
locale	Add a temp-install prerequisite to "check"-like targets not having one.	2017-11-05 18:52:38 -08:00
mb	Revert "Fix broken multibyte regression tests."	2016-01-26 08:29:15 +09:00
modules	Schema-qualify references in test_ddl_deparse test script.	2018-02-26 12:22:39 -05:00
perl	Fix RecursiveCopy.pm to cope with disappearing files.	2017-09-11 22:02:58 -04:00
recovery	In tests, await an LSN no later than the recovery target.	2017-12-31 22:01:27 -08:00
regress	Fix improper uses of canonicalize_qual().	2018-03-11 18:10:42 -04:00
ssl	In SSL tests, don't scribble on permissions of a repo file.	2017-05-15 23:27:51 -04:00
thread	Update copyright for 2016	2016-01-02 13:33:40 -05:00
Makefile	Install TAP test infrastructure so it's available for extension testing.	2016-09-23 15:50:00 -04:00
README	Minor tweaks for new src/test/recovery	2016-02-29 18:16:59 -03:00

README

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.

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

isolation/
  Tests for concurrent behavior at the SQL level

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

thread/
  A thread-safety-testing utility used by configure