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https://issues.apache.org/jira/browse/CASSANDRA-9471?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14612250#comment-14612250
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Benedict commented on CASSANDRA-9471:
-------------------------------------
So, on further consideration, I think I will postpone this patch until the
in-progress refactoring is done. The reason being that it may be there is a
better, slightly wider-viewed, approach to improving this. If so, these
improvements to the BTree won't go completely to waste: at the very least, the
improved iterator, improved tests, and wider deployment of the btree are all
worth incorporating. However the indexability - whilst very nifty, and
relatively simple - is only really helpful while there is a distinction between
Columns and RowDataBlock, which may not be necessary to maintain.
I have a feeling we can both create a more compact and efficient Columns
representation. I will consider it all a bit more once the lay of the land has
settled down.
> Columns should be backed by a BTree, not an array
> -------------------------------------------------
>
> Key: CASSANDRA-9471
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9471
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Benedict
> Assignee: Benedict
> Fix For: 3.0 beta 1
>
>
> Follow up to 8099.
> We have pretty terrible lookup performance as the number of columns grows
> (linear). In at least one location, this results in quadratic performance.
> We don't however want this structure to be either any more expensive to
> build, nor to store. Some small modifications to BTree will permit it to
> serve here, by permitting efficient lookup by index, and calculation _of_
> index for a given key.
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