Return-Path: Delivered-To: apmail-cassandra-dev-archive@www.apache.org Received: (qmail 32363 invoked from network); 29 Mar 2010 12:13:44 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 29 Mar 2010 12:13:44 -0000 Received: (qmail 18135 invoked by uid 500); 29 Mar 2010 12:13:44 -0000 Delivered-To: apmail-cassandra-dev-archive@cassandra.apache.org Received: (qmail 18118 invoked by uid 500); 29 Mar 2010 12:13:44 -0000 Mailing-List: contact dev-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@cassandra.apache.org Delivered-To: mailing list dev@cassandra.apache.org Received: (qmail 18110 invoked by uid 99); 29 Mar 2010 12:13:44 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 29 Mar 2010 12:13:44 +0000 X-ASF-Spam-Status: No, hits=-0.6 required=10.0 tests=AWL,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of jbellis@gmail.com designates 74.125.82.44 as permitted sender) Received: from [74.125.82.44] (HELO mail-ww0-f44.google.com) (74.125.82.44) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 29 Mar 2010 12:13:39 +0000 Received: by wwb31 with SMTP id 31so923843wwb.31 for ; Mon, 29 Mar 2010 05:13:17 -0700 (PDT) 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 :from:date:received:message-id:subject:to:content-type :content-transfer-encoding; bh=PQj/Q+kod0m9x/zL0hJtXTiW7vB5Lb+lpl0wX1Fo9Cg=; b=DsdiaKPxm+BJC7Wbnuo/lhDV2U6AMQaPKN5VavAdN4ErpYAfcK9sFoSSS23kRbllcx EilZ+GWPLvV/VPYLaKSYtPWT9mEWdJDreGc/8vvVFjHnUlcUEqTZ8DMJ7Mr/695RuvjC lVfEkdpmdY6ZQEd98ToreSyH7JYG+6bEvMWds= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type:content-transfer-encoding; b=OzjROoSRbCyQnUW7L1RuKS5Aw90INgRScQrH/yPbAyL7oyk8rSx9X460xZpTMbNMzc mvZN8owvQZwgFjo4i7ozfVwb7LCNa7uQc9jiISblFHTSUUsnebE3kjUfuQM/3xJPkMgC yb9BfPelmk8Wwxm53Y+TV0obwxANKhQjwTO9E= MIME-Version: 1.0 Received: by 10.216.25.204 with HTTP; Mon, 29 Mar 2010 05:12:56 -0700 (PDT) In-Reply-To: <87aatrmjkf.fsf@troilus.org> References: <500005.42244.qm@web51404.mail.re2.yahoo.com> <87aatrmjkf.fsf@troilus.org> From: Jonathan Ellis Date: Mon, 29 Mar 2010 07:12:56 -0500 Received: by 10.216.171.7 with SMTP id q7mr3044787wel.40.1269864797252; Mon, 29 Mar 2010 05:13:17 -0700 (PDT) Message-ID: Subject: Re: Cassandra on top of B-Tree To: dev@cassandra.apache.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Mon, Mar 29, 2010 at 6:52 AM, Michael Poole wrote: > SSTables aren't written on every update. =A0Why would a B-Tree > implementation differ? Because traditional B-trees are update-in-place, and although CouchDB has an append-only B-tree, it's limited to one writer at a time which is (one reason) why they get 6x less throughput than we do on writes.