mirror of
https://git.postgresql.org/git/postgresql.git
synced 2026-02-20 13:27:00 +08:00
ccaa3569f5
Since commit 8f321bd16c functional dependencies can handle IN clauses, which however introduced a possible (and surprising) inconsistency, because IN clauses may be expressed as an OR clause, which are still considered incompatible. For example a IN (1, 2, 3) may be rewritten as (a = 1 OR a = 2 OR a = 3) The IN clause will work fine with functional dependencies, but the OR clause will force the estimation to fall back to plain per-column estimates, possibly introducing significant estimation errors. This commit recognizes OR clauses equivalent to an IN clause (when all arugments are compatible and reference the same attribute) as a special case, compatible with functional dependencies. This allows applying functional dependencies, just like for IN clauses. This does not eliminate the difference in estimating the clause itself, i.e. IN clause and OR clause still use different formulas. It would be possible to change that (for these special OR clauses), but that's not really about extended statistics - it was always like this. Moreover the errors are usually much smaller compared to ignoring dependencies. Author: Tomas Vondra Reviewed-by: Dean Rasheed Discussion: https://www.postgresql.org/message-id/flat/13902317.Eha0YfKkKy%40pierred-pdoc
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 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 subscription/ Tests for logical replication thread/ A thread-safety-testing utility used by configure