"Herouth Maoz" <herouth@xxxxxxxxxxxxx> writes: > I was instructed to delete old records from one of the tables in our production system. The deletion took hours and I had to stop it in mid-operation and reschedule it as a night job. But then I had to do the same when I got up in the morning and it was still running. > I got an interesting clue, though, when I canceled the deletion the second time around. I got the following error message: > Cancel request sent > ERROR: canceling statement due to user request > CONTEXT: SQL statement "SELECT 1 FROM ONLY "public"."sent_messages" x WHERE $1 OPERATOR(pg_catalog.=) "subscription_id" FOR SHARE OF x" Yup, that's a clue all right. I'll bet a nickel that you don't have an index on the foreign key's referencing column (ie, sent_messages.subscription_id). That means each delete in the referenced table has to seqscan the referencing table to see if the delete would result in an FK violation. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
