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https://issues.apache.org/jira/browse/LUCENE-4509?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13495889#comment-13495889
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Robert Muir commented on LUCENE-4509:
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Docs look good, +1 to commit.
A few suggestions:
* under known limitations maybe replace documents with "individual documents"
to make it clear you are talking about 2 gigabyte documents and not files? I
think someone was confused on that already a little bit.
* rather than repeating the formulas for signed vlong (zigzag), we could link
to it? https://developers.google.com/protocol-buffers/docs/encoding#types
* separately if we find ourselves using this more often, maybe we should just
add it to DataOutput/Input (the vlong version would be enough). We
already use this in kuromoji's ConnectionCosts.java too...
> 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
> Assignee: Adrien Grand
> Priority: Minor
> Attachments: LUCENE-4509.patch, LUCENE-4509.patch
>
>
> 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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