postgres

History

Alvaro Herrera 8d1c1ca70b Reduce cost of test_decoding's new oldest_xmin test Change a whole-database VACUUM into doing just pg_attribute, which is the portion that verifies what we want it to do. The original formulation wastes a lot of CPU time, which leads the test to fail when runtime exceeds isolationtester timeout when it's super-slow, such as under CLOBBER_CACHE_ALWAYS. Per buildfarm member friarbird. It turns out that the previous shape of the test doesn't always detect the condition it is supposed to detect (on unpatched reorderbuffer code): the reason is that there is a good chance of encountering a xl_running_xacts record (logged every 15 seconds) before the checkpoint -- and because we advance the xmin when we receive that WAL record, and we don't advance the xmin twice consecutively without receiving a client message in between, that means the xmin is not advanced enough for the tuple to be pruned from pg_attribute by VACUUM. So the test would spuriously pass. The reason this test deficiency wasn't detected earlier is that HOT pruning removes the tuple anyway, even if vacuum leaves it in place, so the test correctly fails (detecting the coding mistake), but for the wrong reason. To fix this mess, run the s0_get_changes step twice before vacuum instead of once: this seems to cause the xmin to be advanced reliably, wreaking havoc with more certainty. Author: Arseny Sher Discussion: https://postgr.es/m/87h8lkuxoa.fsf@ars-thinkpad		7 years ago
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concurrent_ddl_dml.spec	Handle heap rewrites even better in logical decoding	8 years ago
delayed_startup.spec	Introduce logical decoding.	12 years ago
mxact.spec	Introduce logical decoding.	12 years ago
oldest_xmin.spec	Reduce cost of test_decoding's new oldest_xmin test	7 years ago
ondisk_startup.spec	Fix race condition leading to hanging logical slot creation.	8 years ago
snapshot_transfer.spec	Fix "base" snapshot handling in logical decoding	7 years ago