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Posted to dev@hive.apache.org by Shreepadma Venugopalan <sh...@cloudera.com> on 2013/04/29 22:41:27 UTC
Review Request: HIVE-4435: Column stats: Distinct value estimator should use
hash functions that are pairwise independent
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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/10841/
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Review request for hive.
Description
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Fixes the FM estimator to use hash functions that are pairwise independent.
This addresses bug HIVE-4435.
https://issues.apache.org/jira/browse/HIVE-4435
Diffs
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ql/src/java/org/apache/hadoop/hive/ql/udf/generic/NumDistinctValueEstimator.java 69e6f46
Diff: https://reviews.apache.org/r/10841/diff/
Testing
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The estimates are within the expected error after this fix. Tested on TPCH of varying sizes.
Thanks,
Shreepadma Venugopalan
Re: Review Request: HIVE-4435: Column stats: Distinct value estimator should
use hash functions that are pairwise independent
Posted by Shreepadma Venugopalan <sh...@cloudera.com>.
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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/10841/
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(Updated May 31, 2013, 2:24 a.m.)
Review request for hive, Ashutosh Chauhan and Navis Ryu.
Changes
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Added reviewers.
Description
-------
Fixes the FM estimator to use hash functions that are pairwise independent.
This addresses bug HIVE-4435.
https://issues.apache.org/jira/browse/HIVE-4435
Diffs
-----
ql/src/java/org/apache/hadoop/hive/ql/udf/generic/NumDistinctValueEstimator.java 69e6f46
Diff: https://reviews.apache.org/r/10841/diff/
Testing
-------
The estimates are within the expected error after this fix. Tested on TPCH of varying sizes.
Thanks,
Shreepadma Venugopalan