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From Daniel Doubleday <daniel.double...@gmx.net>
Subject Row Cache / Slice Cache
Date Mon, 03 Jan 2011 16:48:23 GMT
Hi,

we have a couple of use cases with wide rows with a small portion of hot data in them.

Example: 

Chatlog: 

{
	$userid1-$userid2: [{timestamp: message}, {timestamp: message} ...]
}

People tend to check only the most recent pages. So while the current row cache doesn't work
with the wide rows I was thinking of adding optional slice / name configs to the row cache.


For example this would say: "cache the last 50 coloumns only"

<ColumnFamily Name="Chat" CompareWith="BytesType"
   RowsCached="10000" RowCacheLimit="50" RowCacheReversed="true"
/>

This would be limited to configurations that allow to easily determine if the read / write
should go to the cache or not. I would try to make it as simple as possible by the restriction
that reads can either be served entirely by the cache or not use it at all.

I haven't found anything in jira yet and I guess this might be too app-specific to be generally
interesting but wanted to ask if anybody out there already did / tried something in that direction.

Cheers,

Daniel Doubleday
smeet.com, Berlin
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