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https://issues.apache.org/jira/browse/CASSANDRA-3952?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13223085#comment-13223085
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Peter Schuller commented on CASSANDRA-3952:
-------------------------------------------
This is already tracked by CASSANDRA-3989 being re-opened.
> avoid quadratic startup time in LeveledManifest
> -----------------------------------------------
>
> Key: CASSANDRA-3952
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3952
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Jonathan Ellis
> Assignee: Dave Brosius
> Priority: Minor
> Labels: lhf
> Fix For: 1.1.1
>
> Attachments: speed_up_level_of.diff
>
>
> Checking that each sstable is in the manifest on startup is O(N**2) in the
> number of sstables:
> {code}
> . // ensure all SSTables are in the manifest
> for (SSTableReader ssTableReader : cfs.getSSTables())
> {
> if (manifest.levelOf(ssTableReader) < 0)
> manifest.add(ssTableReader);
> }
> {code}
> {code}
> private int levelOf(SSTableReader sstable)
> {
> for (int level = 0; level < generations.length; level++)
> {
> if (generations[level].contains(sstable))
> return level;
> }
> return -1;
> }
> {code}
> Note that the contains call is a linear List.contains.
> We need to switch to a sorted list and bsearch, or a tree, to support
> TB-levels of data in LeveledCompactionStrategy.
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