4 Commits (057012b205a082ec930cd7bb7f6663516be011e2)

Author	SHA1	Message	Date
Tom Lane	ea68ea6320	Repair incorrect handling of AfterTriggerSharedData.ats_modifiedcols. ... This patch fixes two distinct errors that both ultimately trace to commit 71d60e2aa, which added the ats_modifiedcols field. The more severe error is that ats_modifiedcols wasn't accounted for in afterTriggerAddEvent's scanning loop that looks for a pre-existing duplicate AfterTriggerSharedData. Thus, a new event could be incorrectly matched to an AfterTriggerSharedData that has a different value of ats_modifiedcols, resulting in the wrong tg_updatedcols bitmap getting passed to the trigger whenever it finally gets fired. We'd not noticed because (a) few triggers consult tg_updatedcols, and (b) we had no tests exercising a case where such a trigger was called as an AFTER trigger. In the test case added by this commit, contrib/lo's trigger fails to remove a large object when expected because (without this fix) it thinks the LO OID column hasn't changed. The other problem was introduced by commit ce5aaea8c, which copied the modified-columns bitmap into trigger-related storage. It made a copy for every trigger event, whereas what we really want is to make a new copy only when we make a new AfterTriggerSharedData entry. (We could imagine adding extra logic to reduce the number of bitmap copies still more, but it doesn't look worthwhile at the moment.) In a simple test of an UPDATE of 10000000 rows with a single AFTER trigger, this thinko roughly tripled the amount of memory consumed by the pending-triggers data structures, from 160446744 to 480443440 bytes. Fixing the first problem requires introducing a bms_equal() call into afterTriggerAddEvent's scanning loop, which is slightly annoying from a speed perspective. However, getting rid of the excessive bms_copy() calls from the second problem balances that out; overall speed of trigger operations is the same or slightly better, in my tests. Discussion: https://postgr.es/m/3496294.1737501591@sss.pgh.pa.us Backpatch-through: 13	12 months ago
Michael Paquier	3ef038fc4f	contrib/lo: Add test for function lo_oid() ... Author: Ronan Dunklau Discussion: https://postgr.es/m/ZzMSJkiNZhimjXWx@paquier.xyz	1 year ago
Peter Eisentraut	71d60e2aa0	Add tg_updatedcols to TriggerData ... This allows a trigger function to determine for an UPDATE trigger which columns were actually updated. This allows some optimizations in generic trigger functions such as lo_manage and tsvector_update_trigger. Reviewed-by: Daniel Gustafsson <daniel@yesql.se> Discussion: https://www.postgresql.org/message-id/flat/11c5f156-67a9-0fb5-8200-2a8018eb2e0c@2ndquadrant.com	6 years ago
Peter Eisentraut	4cb89d8306	lo: Add test suite ... Reviewed-by: David Steele <david@pgmasters.net>	8 years ago