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https://issues.apache.org/jira/browse/CASSANDRA-9471?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14613093#comment-14613093
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Sylvain Lebresne commented on CASSANDRA-9471:
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bq. for the normal worries of code atrophy
Yes, that is something to take into account. However, it's also a utility
class, one that is meant to be used a lot in the codebase. And the indexability
code both already written. So if it "doesn't introduce significant complexity",
it does feels like a relatively good deal. Basically, I would hate to spend
more time pulling the already written functionality out to maybe end up someday
having a good use of this, but ending up doing something less efficient just
because it's not there. Besides, it's totally possible it will be used by
{{Columns}} in the end :)
Anyway, I don't want to sound insistent, it's not that I absolutely want it.
Just offering that maybe simply rebasing that ticket now would avoid pushing
that to when we might be even shorter on resources than we are, doesn't
precludes considering better alternative for {{Columns}} later, and won't waste
all that much work if we do end up changing {{Columns}} but keep the
indexability as "generally useful".
> 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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