Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id A4AA19FB20D for ; Tue, 31 Oct 2006 18:24:32 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 57776-02 for ; Tue, 31 Oct 2006 18:24:27 -0400 (AST) X-Greylist: delayed 00:28:53.910126 by SQLgrey- Received: from svr4.postgresql.org (svr4.postgresql.org [66.98.251.159]) by postgresql.org (Postfix) with ESMTP id EA2FB9FB3F6 for ; Tue, 31 Oct 2006 18:24:23 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.3 Received: from ls405.htnet.hr (ls405.t-com.hr [195.29.150.135]) by svr4.postgresql.org (Postfix) with ESMTP id B0AC65AF884 for ; Tue, 31 Oct 2006 21:55:28 +0000 (GMT) Received: from ls422.t-com.hr (ls422.t-com.hr [195.29.150.237]) by ls405.htnet.hr (Postfix) with ESMTP id 0BB891437E5 for ; Tue, 31 Oct 2006 22:55:25 +0100 (CET) Received: from ls422.t-com.hr (localhost.localdomain [127.0.0.1]) by ls422.t-com.hr (Qmlai) with ESMTP id D8ED6C9004A for ; Tue, 31 Oct 2006 22:55:24 +0100 (CET) X-Envelope-Sender-Info: KDHLkYIFXCRHG7zIR7FVXoSz8xNhH+9BcjSbb/Tcw/g4WtwjvGvnMGQkz7gVlqga X-Envelope-Sender: ivoras@fer.hr Received: from [10.0.0.100] (89-172-44-80.adsl.net.t-com.hr [89.172.44.80])by ls422.t-com.hr (Qmlai) with ESMTP id 78972130803Cfor ; Tue, 31 Oct 2006 22:55:24 +0100 (CET) Message-ID: <4547C65C.6090208@fer.hr> Date: Tue, 31 Oct 2006 22:55:40 +0100 From: Ivan Voras User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: MVCC & indexes? X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-imss-version: 2.043 X-imss-result: Passed X-imss-scores: Clean:71.31485 C:2 M:3 S:5 R:5 X-imss-settings: Baseline:1 C:1 M:1 S:1 R:1 (0.0000 0.0000) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=1.695 tagged_above=0 required=5 tests=BAYES_50, FORGED_RCVD_HELO, RCVD_IN_BL_SPAMCOP_NET, UNPARSEABLE_RELAY X-Spam-Level: * X-Archive-Number: 200610/635 X-Sequence-Number: 21764 Ok, so MVCC is the best thing since a guy put a round stone on a stick and called it "the wheel", but I've seen several references on this list about "indexes not being under MVCC" - at least that's how I read it, the original posts were explaining why indexes can't be used for solving MIN()/MAX()/COUNT() aggregates. Is this correct? In particular, I'm trying to find out is there (b)locking involved when concurrently updating and/or inserting records in an indexed table. My guess is that, since PG does copy+delete on updating, even updating a non-indexed field will require fixups in the index tree (to point to the new record) and thus (b)locking.