From user-return-3904-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org Mon Apr 05 08:09:57 2010 Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 45888 invoked from network); 5 Apr 2010 08:09:57 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 5 Apr 2010 08:09:57 -0000 Received: (qmail 78495 invoked by uid 500); 5 Apr 2010 08:09:57 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 78456 invoked by uid 500); 5 Apr 2010 08:09:56 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 78448 invoked by uid 99); 5 Apr 2010 08:09:56 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 05 Apr 2010 08:09:56 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [38.102.63.181] (HELO smtp-2.01.com) (38.102.63.181) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 05 Apr 2010 08:09:49 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp-2.01.com (Postfix) with ESMTP id 0E4121AD596 for ; Mon, 5 Apr 2010 03:09:29 -0500 (CDT) Received: from smtp-2.01.com ([127.0.0.1]) by localhost (smtp-2.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Kh-+HNKM8h2f for ; Mon, 5 Apr 2010 03:09:28 -0500 (CDT) Received: by smtp-2.01.com (Postfix, from userid 99) id E0B611AD468; Mon, 5 Apr 2010 03:09:28 -0500 (CDT) Received: from [192.168.1.122] (cpe-70-112-179-175.austin.res.rr.com [70.112.179.175]) by smtp-2.01.com (Postfix) with ESMTPSA id 9C26B1AD597 for ; Mon, 5 Apr 2010 03:09:28 -0500 (CDT) Message-ID: <4BB99AB8.9010408@fourkitchens.com> Date: Mon, 05 Apr 2010 08:09:28 +0000 From: David Strauss Organization: Four Kitchens User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: user@cassandra.apache.org Subject: Re: Cassandra Design or another solution References: <4BB95C90.7040307@fourkitchens.com> In-Reply-To: X-Enigmail-Version: 1.0.1 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig6CAD913CD38B23B016715F22" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig6CAD913CD38B23B016715F22 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I need the question about monotonicity answered, too. You should also know: Cassandra is not ideal for directly tracking values you increment or decrement. On 2010-04-05 08:04, JKnight JKnight wrote: > Thanks for for reply, David. >=20 > I will tell more the detail about the system. My system is used to stor= e > the score (point) user earn when they play game. >=20 > "Mark" is the score. > User's score changes when user win game, buy or sell anything. >=20 > Sorry I make a mistake. My data model is: >=20 > Mark{ //Column Family > gameId:{ //row key > mark_userId: ""// (column name : value), > mark2_userId2: "" > }, > gameId2:{//row key > mark_userId: "" > } > } >=20 >=20 > On Sun, Apr 4, 2010 at 11:44 PM, David Strauss > wrote: >=20 > On 2010-04-05 02:48, JKnight JKnight wrote: > > I want to design the data storage to store user's mark for a larg= e > > amount of user. When system run, user's mark changes frequently. >=20 > What is a "mark"? >=20 > > I want to list top 10 user have largest mark. >=20 > Do the "marks" increase monotonically? What other properties do the= y > have? >=20 > > Could we use Cassandra for store this data? > > > > Ex, here my Cassandra data model design: > > Mark{ > > userId{ > > mark_userId > > }, > > } >=20 > I do not understand that notation. What parts are the CF, key/row, = and > column? >=20 > > When user's mark changes, we remove old mark_userId and add new > > mark_userId. > > Because user's mark change frequently and with large amount of > user, I > > think Cassandra can not satisfy. >=20 > On the contrary, Cassandra excels at tracking rapidly changing data= and > even shards rows to scale I/O horizontally. >=20 > -- > David Strauss > | david@fourkitchens.com > Four Kitchens > | http://fourkitchens.com > | +1 512 454 6659 [office] > | +1 512 870 8453 [direct] >=20 >=20 >=20 >=20 > --=20 > Best regards, > JKnight --=20 David Strauss | david@fourkitchens.com | +1 512 577 5827 [mobile] Four Kitchens | http://fourkitchens.com | +1 512 454 6659 [office] | +1 512 870 8453 [direct] --------------enig6CAD913CD38B23B016715F22 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.10 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAku5mrgACgkQZ52GCE5ilTPhAQCfY5Pj5SVJirlnzrNOOEvHKYQ1 F3gAoIdOhxH3SDcGV8Yu2AcJAdvd34je =RhtI -----END PGP SIGNATURE----- --------------enig6CAD913CD38B23B016715F22--