Received: from maia.hub.org (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id D71D76323E8 for ; Fri, 29 May 2009 01:16:34 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 44303-09 for ; Fri, 29 May 2009 01:16:33 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from wf-out-1314.google.com (wf-out-1314.google.com [209.85.200.172]) by mail.postgresql.org (Postfix) with ESMTP id 8D7426321D9 for ; Fri, 29 May 2009 01:16:33 -0300 (ADT) Received: by wf-out-1314.google.com with SMTP id 28so1794128wfc.28 for ; Thu, 28 May 2009 21:16:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :message-id:references:mime-version:content-type:content-disposition :in-reply-to:user-agent; bh=duVrh+pOXPi8NHlAm+JZ9QK2e+lHp3M11CThZRRb8U4=; b=g9PnNV5hPkyxndztFCu+7UNkijS99RJj3f52X7RjkHRDc6qaEpfVmrX83klEpR3ez5 uHGhl76cTWevN18NIOg8xf6eZHkhBjA9vuO2PJXJ2P6oIUPMXfDKApb95YhVMSSQGUtx sx0V1I57Ll5Rk0RS+iLG6QmwHwbvgsn/RsJ+g= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=PXm1Ifsrkl2dmhcIe60PHgOAGJQxcQIKG6gP4uQcXggjVbQkSd+1ELqY5jO87Rndq8 mwaPI/CGKli5t7V0ukGsGX9ZInrzBqbaR/FcebBCWte1Wu1agtfsb9gititUKixWw41Q BOwbM+XSb/hT7jPuGcZdqyljsqiyjBFuqoD0U= Received: by 10.143.3.7 with SMTP id f7mr631536wfi.51.1243570592481; Thu, 28 May 2009 21:16:32 -0700 (PDT) Received: from eddie ([67.182.227.82]) by mx.google.com with ESMTPS id 30sm2422961wfd.1.2009.05.28.21.16.30 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 28 May 2009 21:16:31 -0700 (PDT) Date: Thu, 28 May 2009 22:16:23 -0600 From: Joshua Tolley To: Robert Haas Cc: Euler Taveira de Oliveira , "pgsql-hackers@postgresql.org" Subject: Re: explain analyze rows=%.0f Message-ID: <20090529041623.GE15201@eddie> References: <603c8f070905281830g2e5419c4xad2946d149e21f9d@mail.gmail.com> <4A1F4FD5.7060204@timbira.com> <603c8f070905282012h7eb2210btb808f623a2757de0@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="XStn23h1fwudRqtG" Content-Disposition: inline In-Reply-To: <603c8f070905282012h7eb2210btb808f623a2757de0@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) 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: 200905/1368 X-Sequence-Number: 138910 --XStn23h1fwudRqtG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 28, 2009 at 11:12:42PM -0400, Robert Haas wrote: > On Thu, May 28, 2009 at 11:00 PM, Euler Taveira de Oliveira > > Don't you think is too strange having, for example, 6.67 rows? >=20 > No stranger than having it say 7 when it's really not. Actually mine > mostly come out 1 when the real value is somewhere between 0.5 and > 1.49. :-( +1. It would help users realize more quickly that some of the values in the EXPLAIN output are, for instance, *average* number of rows *per iteration* = of a nested loop, say, rather than total rows found in all loops. That's an important distinction that isn't immediately clear to the novice EXPLAIN reader, but would become so very quickly as users tried to figure out how a scan could come up with a fractional row. - Josh / eggyknap --XStn23h1fwudRqtG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkofYZcACgkQRiRfCGf1UMMDMQCdFWJ3AnjHMtv6ZgkN/rPkOWTO 0iMAn0Dmm8XuDuE7XV78k5f5w59UpLH8 =uKx+ -----END PGP SIGNATURE----- --XStn23h1fwudRqtG--