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https://issues.apache.org/jira/browse/CASSANDRA-10520?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16184391#comment-16184391
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Adam Holmberg commented on CASSANDRA-10520:
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Thanks for the heads up, Paulo. From my cursory read of the patch, it looks
like this is just a new compression parameter, not a new top-level table
option. I believe the drivers treat compression parameters as an opaque map.
Are you saying it doesn't work in current cqlsh?
> Compressed writer and reader should support non-compressed data.
> ----------------------------------------------------------------
>
> Key: CASSANDRA-10520
> URL: https://issues.apache.org/jira/browse/CASSANDRA-10520
> Project: Cassandra
> Issue Type: Improvement
> Components: Local Write-Read Paths
> Reporter: Branimir Lambov
> Assignee: Branimir Lambov
> Labels: client-impacting, messaging-service-bump-required
> Fix For: 4.0
>
> Attachments: ReadWriteTestCompression.java
>
>
> Compressing uncompressible data, as done, for instance, to write SSTables
> during stress-tests, results in chunks larger than 64k which are a problem
> for the buffer pooling mechanisms employed by the
> {{CompressedRandomAccessReader}}. This results in non-negligible performance
> issues due to excessive memory allocation.
> To solve this problem and avoid decompression delays in the cases where it
> does not provide benefits, I think we should allow compressed files to store
> uncompressed chunks as alternative to compressed data. Such a chunk could be
> written after compression returns a buffer larger than, for example, 90% of
> the input, and would not result in additional delays in writing. On reads it
> could be recognized by size (using a single global threshold constant in the
> compression metadata) and data could be directly transferred into the
> decompressed buffer, skipping the decompression step and ensuring a 64k
> buffer for compressed data always suffices.
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