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https://issues.apache.org/jira/browse/PIG-1501?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12897005#action_12897005
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Yan Zhou commented on PIG-1501:
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The default is *not* using the compression on the intermediate data, which is
the existing behavoir.
For RC file, it is just a bit better in terms of compression ration than
TFile. In terms of performance, the difference is within background noise.
Stitching costs should be minimal. Actually, the full "projection" is the
biggest advantage of RCFile over other columnar storage like zebra. I was
surprised to see the compression improvement over TFile is marginal. The only
cause I can think of is that the compression ratio is too sensitive to the data
to pre-determine or even pre-estimate.
lzo is under GPL. But it appears that Hadoop installation has it, at least in
my test cluster.
> need to investigate the impact of compression on pig performance
> ----------------------------------------------------------------
>
> Key: PIG-1501
> URL: https://issues.apache.org/jira/browse/PIG-1501
> Project: Pig
> Issue Type: Test
> Reporter: Olga Natkovich
> Assignee: Yan Zhou
> Fix For: 0.8.0
>
> Attachments: compress_perf_data.txt, compress_perf_data_2.txt
>
>
> We would like to understand how compressing map results as well as well as
> reducer output in a chain of MR jobs impacts performance. We can use PigMix
> queries for this investigation.
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