X-Original-To: pgsql-sql-postgresql.org@postgresql.org Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 9E2B19FB1D5 for ; Tue, 19 Sep 2006 16:15:23 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 57950-02 for ; Tue, 19 Sep 2006 19:15:12 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id A9D6A9FA175 for ; Tue, 19 Sep 2006 16:15:11 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id k8JJF9rx015726; Tue, 19 Sep 2006 15:15:09 -0400 (EDT) To: CG cc: pgsql-sql@postgresql.org Subject: Re: Nested loops are killing throughput In-reply-to: <20060919185913.21542.qmail@web37908.mail.mud.yahoo.com> References: <20060919185913.21542.qmail@web37908.mail.mud.yahoo.com> Comments: In-reply-to CG message dated "Tue, 19 Sep 2006 11:59:13 -0700" Date: Tue, 19 Sep 2006 15:15:09 -0400 Message-ID: <15725.1158693309@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200609/134 X-Sequence-Number: 26345 CG writes: >> If packet_status is large, that seems like a perfectly reasonable plan >> to me. If not ... what data type is packet_uuid? Is its equality op >> marked mergeable or hashable? > It is of type uniqueidentifier ... Is that the one off gborg? It's broken because the equality function is marked volatile, and so the planner is afraid to try to use it for merging or hashing. (It's also not marked strict, which means you can trivially crash the backend by passing it a null ...) regards, tom lane