"Jim C. Nasby" <jnasby@xxxxxxxxxxxxx> writes: > On Sun, May 14, 2006 at 10:50:50PM -0400, Tom Lane wrote: >> Enzo Daddario <enzo@xxxxxxxxxxxxxxx> writes: >>> I am now required the remove thousands of obsolete records from table >>> "X" and even though I have removed all related rows in all related >>> tables, the deletion of rows in table "X" is taking WAY TOO LONG. >> >> You need to put indexes on the referencing columns. Then start a fresh >> session for doing the actual deletes (FK check plans are usually cached >> per-session). > Would SET CONSTRAINTS ... DEFERRED not help, or does it still use the > same machinery to do the checking, regardless of how much data there is > to check? It's the same machinery. We've speculated about having the thing switch over to doing a full-table recheck (comparable to what ADD CONSTRAINT FOREIGN KEY does) once the number of pending individual row checks exceeds some threshold, but that's not done yet --- and it's not clear how to do it in a concurrent fashion, so don't hold your breath ... regards, tom lane
