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https://issues.apache.org/jira/browse/CASSANDRA-9830?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15011504#comment-15011504
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Paulo Motta edited comment on CASSANDRA-9830 at 11/18/15 5:43 PM:
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Rebased to latest trunk and squashed.
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[branch|https://github.com/apache/cassandra/compare/trunk...pauloricardomg:9830-trunk-rebased]
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[testall|http://cassci.datastax.com/view/Dev/view/paulomotta/job/pauloricardomg-9830-trunk-rebased-testall/lastCompletedBuild/testReport/]
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[dtest|http://cassci.datastax.com/view/Dev/view/paulomotta/job/pauloricardomg-9830-trunk-rebased-dtest/lastCompletedBuild/testReport/]
was (Author: pauloricardomg):
Rebased to latest trunk and squased.
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[branch|https://github.com/apache/cassandra/compare/trunk...pauloricardomg:9830-trunk-rebased]
*
[testall|http://cassci.datastax.com/view/Dev/view/paulomotta/job/pauloricardomg-9830-trunk-rebased-testall/lastCompletedBuild/testReport/]
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[dtest|http://cassci.datastax.com/view/Dev/view/paulomotta/job/pauloricardomg-9830-trunk-rebased-dtest/lastCompletedBuild/testReport/]
> Option to disable bloom filter in highest level of LCS sstables
> ---------------------------------------------------------------
>
> Key: CASSANDRA-9830
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9830
> Project: Cassandra
> Issue Type: New Feature
> Components: Compaction
> Reporter: Jonathan Ellis
> Assignee: Paulo Motta
> Priority: Minor
> Labels: performance
> Fix For: 3.x
>
>
> We expect about 90% of data to be in the highest level of LCS in a fully
> populated series. (See also CASSANDRA-9829.)
> Thus if the user is primarily asking for data (partitions) that has actually
> been inserted, the bloom filter on the highest level only helps reject
> sstables about 10% of the time.
> We should add an option that suppresses bloom filter creation on top-level
> sstables. This will dramatically reduce memory usage for LCS and may even
> improve performance as we no longer check a low-value filter.
> (This is also an idea from RocksDB.)
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