Received: from maia.hub.org (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 35E90633E47 for ; Wed, 4 Nov 2009 18:17:10 -0400 (AST) 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 19491-04 for ; Wed, 4 Nov 2009 22:17:02 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-iw0-f186.google.com (mail-iw0-f186.google.com [209.85.223.186]) by mail.postgresql.org (Postfix) with ESMTP id 7B1EB6326D1 for ; Wed, 4 Nov 2009 18:17:02 -0400 (AST) Received: by iwn16 with SMTP id 16so5109164iwn.29 for ; Wed, 04 Nov 2009 14:17:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=TeHHn5GJcm+RDOE12jpeNNgWf07XdRrd7n9IKkINNCs=; b=Sslm+a75jdVvCh3ArNNYGEKq6eTTocO7UWEcVp4gLn8Fi9jWySblX91TrKfaofPMji e3lNOqtZjPKwimKcP/j3eu6Q6YGtqPz4VUgT6x4E2D37dpqOJAG/zxyKGhMgzHfi2dk6 E/B2HqHxMfjWkCwmZxXDxI2A9piT1Q1P+Jon8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=vFLgKBNT729LF53598GbyLieqwgZ3wmackA2vM3p9XFfsxFmQ/K2/OudlmA0z2hHo6 F5T+0ewvlKp2dy1txALOR+ysM+e+v6NMcLQ8m76Beb312EMgaJ6FluTx0HbRojbSj8P1 8Cxc7kFAsDk8exAePj7xG5YroEMgP0HWdQViM= MIME-Version: 1.0 Received: by 10.231.120.84 with SMTP id c20mr4970000ibr.47.1257373020927; Wed, 04 Nov 2009 14:17:00 -0800 (PST) In-Reply-To: <27333.1257372664@sss.pgh.pa.us> References: <396486430911041403u639c750bn488ada60822448c0@mail.gmail.com> <27333.1257372664@sss.pgh.pa.us> Date: Wed, 4 Nov 2009 14:17:00 -0800 Message-ID: <396486430911041417o40cf1939k6ff703ca704a3e14@mail.gmail.com> Subject: Re: Learning about WITH RECURSIVE From: Richard Broersma To: Tom Lane Cc: sql pgsql Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.599 tagged_above=-10 required=5 tests=BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 200911/22 X-Sequence-Number: 33373 On Wed, Nov 4, 2009 at 2:11 PM, Tom Lane wrote: > Richard Broersma writes: >> Can anyone one explain why a "WITH RECURSIVE" query has the same >> results regardless whether UNION or UNION ALL is specified? > > Well, if the rows are all different anyway, UNION isn't going to > eliminate any ... Okay thanks. I see that I need to spend more time with the on-line docs. -- Regards, Richard Broersma Jr. Visit the Los Angeles PostgreSQL Users Group (LAPUG) http://pugs.postgresql.org/lapug