Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 02EBA64FCDA for ; Tue, 23 Dec 2008 01:02:08 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 02097-03 for ; Tue, 23 Dec 2008 01:02:05 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by mail.postgresql.org (Postfix) with ESMTP id 2EF9764FCCF for ; Tue, 23 Dec 2008 01:02:05 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id mBN524mM015559; Tue, 23 Dec 2008 00:02:04 -0500 (EST) To: "Lipker, Joseph" cc: "pgsql-admin@postgresql.org" Subject: Re: Migration \ OID question In-reply-to: References: <9562.1229745736@sss.pgh.pa.us> Comments: In-reply-to "Lipker, Joseph" message dated "Mon, 22 Dec 2008 10:07:21 -0800" Date: Tue, 23 Dec 2008 00:02:03 -0500 Message-ID: <15558.1230008523@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200812/182 X-Sequence-Number: 31015 "Lipker, Joseph" writes: > You mentioned "performance glitches". What would those be? Errors or system performance slowdowns. Slowdowns --- specifically, the behavior is "generate next sequential OID, probe index to see if it exists in table, repeat until not". So if you've got a long run of consecutive OIDs in the same table, when the OID counter reaches that point it could take a while to assign the next free OID successfully. This would manifest as a slower than expected INSERT. regards, tom lane