(for 8.4 ...) I'd like to introduce triggers that fire when we issue a truncate:
CREATE TRIGGER name [BEFORE | AFTER ] TRUNCATE ON table FOR EACH STATEMENT EXECUTE PROCEDURE function (arguments); The truncate trigger would fire separately from a statement-level DELETE statement, to allow us to distinguish those two events. There would be nothing to stop both triggers executing the same function however, if desired. COPY already provides a model for how a utility command can execute triggers. tablecmds.c would invoke ExecBSTruncateTriggers() and ExecASTruncateTriggers(), both of which would live in triggers.c There doesn't seem much too difficult about the implementation or behaviour, but I want to make sure we have the discussion at least, to see if anybody has concerns or additional requirements. Notes: As the syntax shows, these would be statement-level triggers (only). Requesting row level triggers will cause an error. [As Chris Browne explained, if people really want, they can use these facilities to create a Before Statement trigger that executes a DELETE, which then fires row level calls.] I also plan to add a TRUNCATE privilege, though that will be a separate patch in a later post. That will widen the use case of TRUNCATE, which should be OK to do once we've covered the replication concerns. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
