Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 73045 invoked from network); 14 May 2010 00:11:26 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 14 May 2010 00:11:26 -0000 Received: (qmail 99574 invoked by uid 500); 14 May 2010 00:11:25 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 99555 invoked by uid 500); 14 May 2010 00:11:25 -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 99547 invoked by uid 99); 14 May 2010 00:11:25 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 14 May 2010 00:11:25 +0000 X-ASF-Spam-Status: No, hits=2.2 required=10.0 tests=FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of philip142au@gmail.com designates 209.85.210.179 as permitted sender) Received: from [209.85.210.179] (HELO mail-yx0-f179.google.com) (209.85.210.179) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 14 May 2010 00:11:17 +0000 Received: by yxe9 with SMTP id 9so766051yxe.29 for ; Thu, 13 May 2010 17:10:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=ZcEg+Z+kPHEiuM8UyQ/CKGZ/7VAFLkcl9mm1M6CO5cU=; b=Lqy2srWXHIZS4l6w06gr4xxCVoQ/w6c2Z0A4ngsvMiTLZj/GK/NJ1uyJAPguFvK4TX R27F8ASF2N9XVO9CgAgqW/ySYu1fmb+jsM1ElQUE3kH60lfRCFVwxhYBcux3b9lJfcii pYu8uaHGhFTZgQ87UiNhu+ho3pfBSRE7XUIAM= 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 :content-type; b=Un3qb+HGFG5+TX4hoKQaM0bFVyXdfB9yY6OQ381wuLJViXjWFAUKQA0j7Ee5s0gax1 jUqgWi7xYXwuoGrFf7GxT/FK4BEoJZjkKuifixS7Ewfb2NCG1M42+Mn8DzFu+y2kLarF DP/gEqWapnnBJsHcvYinPYYuB7ORkIf6fu7Rc= MIME-Version: 1.0 Received: by 10.151.115.4 with SMTP id s4mr995181ybm.413.1273795856751; Thu, 13 May 2010 17:10:56 -0700 (PDT) Received: by 10.151.50.17 with HTTP; Thu, 13 May 2010 17:10:56 -0700 (PDT) In-Reply-To: References: Date: Fri, 14 May 2010 08:10:56 +0800 Message-ID: Subject: Re: how does cassandra compare with mongodb? From: philip andrew To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=001e680f15848edfb0048682b52f X-Virus-Checked: Checked by ClamAV on apache.org --001e680f15848edfb0048682b52f Content-Type: text/plain; charset=ISO-8859-1 MongoDB encourages you to define your schema in your application code by using mapping classes. This logically infers that it makes no sense to define the schema twice, in the database and in your application code. On Fri, May 14, 2010 at 3:48 AM, Steve Lihn wrote: > What is changing? A more flexible schema or no need to restart (some kind > of hot-reboot)? > > Mongo guys claims that Mongo's advantage is a schema-less design. Basically > you can have any data structure you want and you can change them anyway you > want. This is done in the name of "flexibility", but I am not sure this is a > good practice. People argued for years that perl is bad because it is > typeless and java is strong typed and is better. Now the java community is > developing a database like Mongo that is schema-less. How does this > complements the strong-type argument? > > The less requirement is put on database schema design, the more burden is > put on the application to maintain data integrity. Why is this a good trend? > Can someone kindly explain? > > Steve > > > > > On Thu, May 13, 2010 at 1:22 PM, Vijay wrote: > >> "Cassandra requires the schema to be defined before the database starts, >> MongoDB can have any schema at run-time just like a normal database." >> >> This is changing in 0.7 >> >> Regards, >> >> >> >> --001e680f15848edfb0048682b52f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable MongoDB encourages you to define your schema in your application code by us= ing mapping classes. This logically infers that it makes no sense to define= the schema twice, in the database and in your application code.

On Fri, May 14, 2010 at 3:48 AM, Steve Lihn <stevelihn@gmail.co= m> wrote:
What is changing? A more flexible schema or no need to restart (some kind o= f hot-reboot)?

Mongo guys claims that Mongo's advantage is a sch= ema-less design. Basically you can have any data structure you want and you= can change them anyway you want. This is done in the name of "flexibi= lity", but I am not sure this is a good practice. People argued for ye= ars that perl is bad because it is typeless and java is strong typed and is= better. Now the java community is developing a database like Mongo that is= schema-less. How does this complements the strong-type argument?

The less requirement is put on database schema design, the more burden = is put on the application to maintain data integrity. Why is this a good tr= end? Can someone kindly explain?

Steve




On Thu, May 13, 2010 at 1:22 PM, Vijay <vijay2win@gmail.com> wrote:
"Cassandra requires the schema to be defined befor= e the database starts, MongoDB can have any schema at run-time just like a = normal database."

This is changing in 0.7

Regards,
</VJ>



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