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https://issues.apache.org/jira/browse/LUCENE-10556?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17531676#comment-17531676
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Robert Muir commented on LUCENE-10556:
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{quote}
Currently the logic is to recompress if more than 1% of the blocks are
incomplete, or if the total number of missing documents across incomplete
blocks is more than the configured maximum number of documents per block.
{quote}
It is a logical AND actually. So only if we are 1% dirty, AND there's enough to
"dirty docs" to form a new fully complete block (e.g. we make permanent
progress). This prevents wasteful recompression that doesn't gain us anything
in the long-term.
+1 to re-evaluate the 1% threshold
> Relax the maximum dirtiness for stored fields and term vectors?
> ---------------------------------------------------------------
>
> Key: LUCENE-10556
> URL: https://issues.apache.org/jira/browse/LUCENE-10556
> Project: Lucene - Core
> Issue Type: Improvement
> Reporter: Adrien Grand
> Priority: Minor
>
> Stored fields and term vectors compress data and have merge-time
> optimizations to copy compressed data directly instead of decompressing and
> recompressing over and over again. However, sometimes incomplete blocks get
> carried over (typically the last block of a flushed segment) and so these
> file formats keep track of how "dirty" their current blocks are to know
> whether stored fields / term vectors for a segment should be re-compressed.
> Currently the logic is to recompress if more than 1% of the blocks are
> incomplete, or if the total number of missing documents across incomplete
> blocks is more than the configured maximum number of documents per block.
> I'd be interested in evaluating what the compression ratio would be if we
> relaxed these conditions a bit, e.g. by allowing up to 5% dirtiness. My gut
> feeling is that the compression ratio could be barely worse while index-time
> CPU usage could be significantly improved.
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