Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id A0366634E52 for ; Thu, 2 Apr 2009 16:50:06 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 72875-01 for ; Thu, 2 Apr 2009 16:49:59 -0300 (ADT) 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 1D5A1634E7C for ; Thu, 2 Apr 2009 16:50:02 -0300 (ADT) 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 n32Jnx7S020203; Thu, 2 Apr 2009 15:49:59 -0400 (EDT) To: Simon Riggs cc: pgsql-hackers@postgresql.org Subject: Re: [COMMITTERS] pgsql: If we expect a hash join to be performed in multiple batches, In-reply-to: <1238692283.5444.123.camel@ebony.2ndQuadrant> References: <20090326171535.6B9BF754ADE@cvs.postgresql.org> <1238692283.5444.123.camel@ebony.2ndQuadrant> Comments: In-reply-to Simon Riggs message dated "Thu, 02 Apr 2009 18:11:23 +0100" Date: Thu, 02 Apr 2009 15:49:59 -0400 Message-ID: <20202.1238701799@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.073 tagged_above=0 required=5 tests=AWL=0.073 X-Spam-Level: X-Archive-Number: 200904/138 X-Sequence-Number: 136241 Simon Riggs writes: > Can we add "batches=N" to the EXPLAIN output for Hash and/or Hash Join? Are you talking about expected batches, or actual batches? If the former, would it be sufficient to distinguish "1" from "more than 1"? If so, maybe changing the node title to "Batched Hash" would do. regards, tom lane