mirror of
https://git.postgresql.org/git/postgresql.git
synced 2026-02-24 07:17:00 +08:00
72daabc7a3
Pushing an upper-level restriction clause into an unflattened subquery-in-FROM is okay when the subquery contains no SRFs in its targetlist, or when it does but the SRFs are unreferenced by the clause *and the clause is not volatile*. Otherwise, we're changing the number of times the clause is evaluated, which is bad for volatile quals, and possibly changing the result, since a volatile qual might succeed for some SRF output rows and not others despite not referencing any of the changing columns. (Indeed, if the clause is something like "random() > 0.5", the user is probably expecting exactly that behavior.) We had most of these restrictions down, but not the one about the upper clause not being volatile. Fix that, and add a regression test to illustrate the expected behavior. Although this is definitely a bug, it doesn't seem like back-patch material, since possibly some users don't realize that the broken behavior is broken and are relying on what happens now. Also, while the added test is quite cheap in the wake of commit a4c35ea1c, it would be much more expensive (or else messier) in older branches. Per report from Tom van Tilburg. Discussion: <CAP3PPDiucxYCNev52=YPVkrQAPVF1C5PFWnrQPT7iMzO1fiKFQ@mail.gmail.com>
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