Ensure that seqscans check for interrupts at least once per page. If a seqscan encounters many consecutive pages containing only dead tuples, it can remain in the loop in heapgettup for a long time, and there was no CHECK_FOR_INTERRUPTS anywhere in that loop. This meant there were real-world situations where a query would be effectively uncancelable for long stretches. Add a check placed to occur once per page, which should be enough to provide reasonable response time without adding any measurable overhead.
Report and patch by Merlin Moncure (though I tweaked it a bit). Back-patch to all supported branches. Branch ------ REL9_1_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/276bea211f08a3b0d6d5753b654322c8efb781d1 Modified Files -------------- src/backend/access/heap/heapam.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
