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https://issues.apache.org/jira/browse/LUCENE-4509?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13485201#comment-13485201
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Adrien Grand commented on LUCENE-4509:
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But if we worry about this worst-case (numDocs == numChunks), maybe we should
just increase the chunk size (for example, ElasticSearch uses 65 kB by default).
(Another option would be to change the compress+flush trigger to something
like : chunk size >= 16 kB AND number of documents in the chunk >= 4.)
> Make CompressingStoredFieldsFormat the new default StoredFieldsFormat impl
> --------------------------------------------------------------------------
>
> Key: LUCENE-4509
> URL: https://issues.apache.org/jira/browse/LUCENE-4509
> Project: Lucene - Core
> Issue Type: Wish
> Components: core/store
> Reporter: Adrien Grand
> Priority: Minor
>
> What would you think of making CompressingStoredFieldsFormat the new default
> StoredFieldsFormat?
> Stored fields compression has many benefits :
> - it makes the I/O cache work for us,
> - file-based index replication/backup becomes cheaper.
> Things to know:
> - even with incompressible data, there is less than 0.5% overhead with LZ4,
> - LZ4 compression requires ~ 16kB of memory and LZ4 HC compression requires
> ~ 256kB,
> - LZ4 uncompression has almost no memory overhead,
> - on my low-end laptop, the LZ4 impl in Lucene uncompresses at ~ 300mB/s.
> I think we could use the same default parameters as in CompressingCodec :
> - LZ4 compression,
> - in-memory stored fields index that is very memory-efficient (less than 12
> bytes per block of compressed docs) and uses binary search to locate
> documents in the fields data file,
> - 16 kB blocks (small enough so that there is no major slow down when the
> whole index would fit into the I/O cache anyway, and large enough to provide
> interesting compression ratios ; for example Robert got a 0.35 compression
> ratio with the geonames.org database).
> Any concerns?
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