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From "Tim Armstrong (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-4846: Upgrade Snappy to 1.1.4
Date Mon, 20 Mar 2017 15:38:32 GMT
Tim Armstrong has posted comments on this change.

Change subject: IMPALA-4846: Upgrade Snappy to 1.1.4
......................................................................


Patch Set 1:

Can you do a quick benchmark to sanity-check the performance scanning compressed parquet?
You can do something like this:

   use tpch_parquet;
   create table biglineitem stored as parquet as select * from lineitem;
   insert into biglineitem select * from biglineitem;
   -- Repeat a few times to get a table that takes a few seconds to scan
   -- Use one thread and one impala daemon to reduce variability
   set mt_dop=1;
   set num_nodes=1;
   select * from biglineitem where l_orderkey = 3;

When running that locally I see snappy taking ~18% of CPU in perf top so hopefully the new
snappy version will shave some time off the query.

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Gerrit-MessageType: comment
Gerrit-Change-Id: I2f3439019ae22bbcf4db7f731e45ba5f7899fcc2
Gerrit-PatchSet: 1
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Laszlo Gaal <laszlo.gaal@cloudera.com>
Gerrit-Reviewer: Tim Armstrong <tarmstrong@cloudera.com>
Gerrit-HasComments: No

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