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From Ben Gambley <>
Subject Re: Seeking advice on Schema and Caching
Date Tue, 15 Nov 2011 21:49:19 GMT
Hi Aditya

Not sure the best way to do in Cassandra but have you considered using
apache solr - you could then include just the row keys pointing back
to Cassandra where the actual data is.

Solr seems quite capable of performing google like searches and is fast.


On 16/11/2011, at 1:50 AM, Aditya Narayan <> wrote:

> Hi
> I need to add 'search users' functionality to my application. (The trigger for fetching
searched items(like google instant search) is made when 3 letters have been typed in).
> For this, I make a CF with String type keys. Each such key is made of first 3 letters
of a user's name.
> Thus all names starting with 'Mar-' are stored in single row (with key="Mar").
> The column names are framed as remaining letters of the names. Thus, a name 'Marcos'
will be stored within rowkey "Mar" & col name "cos". The id will be stored as column value.
Since there could be many users with same name. Thus I would have multple userIds(of users
named "Marcos") to be stored inside columnname "cos" under key "Mar". Thus,
> 1. Supercolumn seems to be a better fit for my use case(so that ids of users with same
name may fit as sub-columns inside a super-column) but since supercolumns are not encouraged
thus I want to use an alternative schema for this usecase if possible. Could you suggest some
ideas on this ?
> 2. Another thing, I would like to row cache this CF so that when the user types in the
next character & the query is made consequently, then this row be retrieved from the cache
without touching DB. It is expected while searching for a single username, the query(as a
part of making instantaneous suggestions) will be made at least 2-3 times. One may also suggest
to fetch all the columns starting with queried string to be retrieved & then filter out
at application level but what about just fecthing the exact no of columns(ids/names of users)
I need to show to the user. Thus instead of keeping all the hundreds of cols in the application
layer what about keeping it within the DB cache.!?
> The space alloted for the cache will be very small so that row remains in cache for a
very short time(enough to serve only for the time duration while user is making a single search!?)

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