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From Sylvain Lebresne <sylv...@datastax.com>
Subject Re: Composite Column Types Storage
Date Thu, 20 Sep 2012 15:49:28 GMT
> As I understand from the link below, burning column index-info onto the
> sstable index files will not only eliminate sstables but also reduce disk
> seeks from 3 to 2 for wide rows.

Yes.

> Shouldn't we be wary of the spike in heap usage by promoting column indexes
> to index file?

If you're talking about the index files getting bigger, that's not
really a problem per-se, mmapped files are not part of the heap and
it's all dealt by the file system.
Now it's true that the column index is also promoted in the index
summary that is loaded in memory. However, how much is loaded in this
summary is still configurable, so overall that shouldn't be a problem
either (fyi,  https://issues.apache.org/jira/browse/CASSANDRA-4478 is
relevant to that discussion too).

--
Sylvain

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