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From: Evan Weaver <evan@cloudbur.st>
Date: Tue, 19 May 2009 09:49:21 -0700
Message-ID: <b6f68fc60905190949l6c06d346scc031be376f98a5d@mail.gmail.com>
Subject: Re: schema example
To: cassandra-user@incubator.apache.org
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Even if it's not actually in real-life use, some examples for common
domains would really help clarify things.

 * blog
 * email storage
 * search index

etc.

Evan

On Mon, May 18, 2009 at 8:19 PM, Jonathan Ellis <jbellis@gmail.com> wrote:
> Does anyone have a simple app schema they can share?
>
> I can't share the one for our main app. =A0But we do need an example
> here. =A0A real one would be nice if we can find one.
>
> I checked App Engine. =A0They don't have a whole lot of examples either.
> =A0They do have a really simple one:
> http://code.google.com/appengine/docs/python/gettingstarted/usingdatastor=
e.html
>
> The most important thing in Cassandra modeling is choosing a good key,
> since that is what most of your lookups will be by. =A0Keys are also how
> Cassandra scales -- Cassandra can handle effectively infinite keys
> (given enough nodes obviously) but only thousands to millions of
> columns per key/CF (depending on what API calls you use -- Jun is
> adding one now that does not deseriailze everything in the whole CF
> into memory. =A0The rest will need to follow this model eventually too).
>
> For this guestbook I think the choice is obvious: use the name as the
> key, and have a single simple CF for the messages. =A0Each column will
> be a message (you can even use the mandatory timestamp field as part
> of your user-visible data. =A0win!). =A0You get the list (or page) of
> users with get_key_range and then their messages with get_slice.
>
> <ColumnFamily ColumnSort=3D"Name" Name=3D"Message"/>
>
> Anyone got another one for pedagogical purposes?
>
> -Jonathan
>


--=20
Evan Weaver