postgres

History

Tom Lane 3c43595217 Quick-hack fix for foreign key cascade vs triggers with transition tables. AFTER triggers using transition tables crashed if they were fired due to a foreign key ON CASCADE update. This is because ExecEndModifyTable flushes the transition tables, on the assumption that any trigger that could need them was already fired during ExecutorFinish. Normally that's true, because we don't allow transition-table-using triggers to be deferred. However, foreign key CASCADE updates force any triggers on the referencing table to be deferred to the outer query level, by means of the EXEC_FLAG_SKIP_TRIGGERS flag. I don't recall all the details of why it's like that and am pretty loath to redesign it right now. Instead, just teach ExecEndModifyTable to skip destroying the TransitionCaptureState when that flag is set. This will allow the transition table data to survive until end of the current subtransaction. This isn't a terribly satisfactory solution, because (1) we might be leaking the transition tables for much longer than really necessary, and (2) as things stand, an AFTER STATEMENT trigger will fire once per RI updating query, ie once per row updated or deleted in the referenced table. I suspect that is not per SQL spec. But redesigning this is a research project that we're certainly not going to get done for v10. So let's go with this hackish answer for now. In passing, tweak AfterTriggerSaveEvent to not save the transition_capture pointer into the event record for a deferrable trigger. This is not necessary to fix the current bug, but it avoids letting dangling pointers to long-gone transition tables persist in the trigger event queue. That's at least a safety feature. It might also allow merging shared trigger states in more cases than before. I added a regression test that demonstrates the crash on unpatched code, and also exposes the behavior of firing the AFTER STATEMENT triggers once per row update. Per bug #14808 from Philippe Beaudoin. Back-patch to v10. Discussion: https://postgr.es/m/20170909064853.25630.12825@wrigleys.postgresql.org		8 years ago
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data	…
expected	Quick-hack fix for foreign key cascade vs triggers with transition tables.	8 years ago
input	Merge large_object.sql test into largeobject.source.	9 years ago
output	Merge large_object.sql test into largeobject.source.	9 years ago
sql	Quick-hack fix for foreign key cascade vs triggers with transition tables.	8 years ago
.gitignore	…
GNUmakefile	Remove ICU tests from default run	9 years ago
Makefile	…
README	…
parallel_schedule	Introduce 64-bit hash functions with a 64-bit seed.	8 years ago
pg_regress.c	Phase 3 of pgindent updates.	9 years ago
pg_regress.h	Initial pgindent run with pg_bsd_indent version 2.0.	9 years ago
pg_regress_main.c	Fix inclusions of postgres_fe.h from .h files.	9 years ago
regress.c	Remove to pre-8.2 coding convention for PG_MODULE_MAGIC	8 years ago
regressplans.sh	…
resultmap	…
serial_schedule	Merge large_object.sql test into largeobject.source.	9 years ago
standby_schedule	…

README

Documentation concerning how to run these regression tests and interpret
the results can be found in the PostgreSQL manual, in the chapter
"Regression Tests".