Hi >>>>> "DK" == Dmitry Koterov <dmitry@xxxxxxxxxx> writes: DK> create table a(i integer); DK> CREATE UNIQUE INDEX a_idx ON a USING btree (i); DK> CREATE FUNCTION a_tr() RETURNS trigger AS DK> $body$ DK> BEGIN DK> DELETE FROM a WHERE i = NEW.i; DK> RETURN NEW; DK> END; DK> $body$ DK> LANGUAGE 'plpgsql'; DK> CREATE TRIGGER a_tr BEFORE INSERT ON a FOR EACH ROW EXECUTE PROCEDURE DK> a_tr(); The DELETE doesn't see the row the other transaction inserted and doesn't delete anything (and doesn't block). This happens later when the row is inserted and the index is updated. You can try the insert and catch the unique violation in a loop (see http://www.postgresql.org/docs/9.1/static/plpgsql-control-structures.html) although that won't work with a BEFORE trigger. Regards, Julian -- Julian v. Bock Projektleitung Software-Entwicklung OpenIT GmbH Tel +49 211 239 577-0 In der Steele 33a-41 Fax +49 211 239 577-10 D-40599 Düsseldorf http://www.openit.de ________________________________________________________________ HRB 38815 Amtsgericht Düsseldorf USt-Id DE 812951861 Geschäftsführer: Oliver Haakert, Maurice Kemmann -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
