Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cassandra.apache.org
Received-SPF: pass (nike.apache.org: domain of prescod@gmail.com designates
 209.85.211.190 as permitted sender)
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:sender:in-reply-to:references:from:date
         :x-google-sender-auth:message-id:subject:to:content-type
         :content-transfer-encoding;
        b=Q+x6mdthm4mZ+8r6t4yZ4BOGW7UaHX2yzpx0NOYe1nsKrsab2kcdPSmYDZMAeri4dF
         Hpx4qdLUyL0sT5lwWV5V3583Om9oEseeXEAdrI621jNrK0iQZY5NPEpNatFzeOLR/qnB
         AUQINB0OAAYbHlNJpQitQyGEg1LRn4nEcj80Y=
MIME-Version: 1.0
Sender: prescod@gmail.com
In-Reply-To: <AANLkTikA05NHSwE3fJXCQCspwS4XvvnJDv3etH_fEEbY@mail.gmail.com>
References: <AD99A904-CD26-4FFC-BD8D-D22CA19B0565@motivecast.com>
	<AANLkTikA05NHSwE3fJXCQCspwS4XvvnJDv3etH_fEEbY@mail.gmail.com>
From: Paul Prescod <paul@prescod.net>
Date: Mon, 10 May 2010 11:26:42 -0700
Message-ID: <AANLkTimTSOXM0vAPMN03Y4gTOMY1T3Qm0O-ndn4eqQ2K@mail.gmail.com>
Subject: Re: Human readable Cassandra limitations
To: user@cassandra.apache.org
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Also:

 * you should Google "eventual consistency" to learn about the
strengths and weaknesses of that.

On Mon, May 10, 2010 at 11:22 AM, Paul Prescod <paul@prescod.net> wrote:
> This is a very, very big topic. For the most part, the issues are
> covered in the various SQL versus NoSQL debates all over the Internet.
> For example:
>
> =C2=A0* Cassandra and its NoSQL siblings have no concept of an in-databas=
e "join"
>
> =C2=A0* Cassandra and its NoSQL siblings do not allow you to update
> multiple "tables" in a single transactions
>
> =C2=A0* Cassandra's API is specific to it, and not portable to any other =
data store
>
> =C2=A0* Cassandra currently has simplistic facilities to deal with variou=
s
> kinds of conflicting write.
>
> =C2=A0* Cassandra is strongly optimized for multiple machine distribution=
s,
> whereas relational databases tend to be optimized for a single
> powerful machine.
>
> =C2=A0* Cassandra and its siblings are weak at ad hoc queries on tables
> that you did not think to index in advance
>
> On Mon, May 10, 2010 at 11:06 AM, Peter Hsu <peter@motivecast.com> wrote:
>> I've seen a lot of threads and posts about why Cassandra is great. =C2=
=A0I'm fairly sold on the features, and the few big deployments on Cassandr=
a give it a lot of credibility.
>>
>> However, I don't believe in magic bullets, so I really want to understan=
d the potential downsides of Cassandra. =C2=A0Right now, I don't really hav=
e a clue as to what Cassandra is bad at. =C2=A0I took a look at http://wiki=
.apache.org/cassandra/CassandraLimitations which is helpful, but doesn't ch=
aracterize its weaknesses in ways that I can really comprehend until I've a=
ctually used Cassandra and understand some of the internals. =C2=A0It seems=
 that the community would benefit from being able to answer some of these q=
uestions in terms of real world use cases.
>>
>> My main questions:
>> =C2=A0* Are there designs in which a SQL database out-performs or out-sc=
ales Cassandra?
>> =C2=A0* Is there a pros vs cons page of Cassandra against an open source=
 SQL database (MySQL or Postgres)?
>>
>> I do plan on attending the training session next Friday in Palo Alto, bu=
t it'd be great if I had some more food for thought before I attend.
>>
>>
>