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Posted to issues@hive.apache.org by "Lefty Leverenz (JIRA)" <ji...@apache.org> on 2015/06/17 07:59:01 UTC
[jira] [Updated] (HIVE-3958) support partial scan for analyze
command - RCFile
[ https://issues.apache.org/jira/browse/HIVE-3958?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Lefty Leverenz updated HIVE-3958:
---------------------------------
Description:
analyze commands allows us to collect statistics on existing tables/partitions. It works great but might be slow since it scans all files.
There are 2 ways to speed it up:
1. collect stats without file scan. It may not collect all stats but good and fast enough for use case. HIVE-3917 addresses it
2. collect stats via partial file scan. It doesn't scan all content of files but part of it to get file metadata. some examples are https://cwiki.apache.org/Hive/rcfilecat.html for RCFile, ORC ( HIVE-3874 ) and HFile of Hbase (Edit: That link should be https://cwiki.apache.org/confluence/display/Hive/RCFileCat.)
This jira is targeted to address the #2. More specifically RCFile format.
was:
analyze commands allows us to collect statistics on existing tables/partitions. It works great but might be slow since it scans all files.
There are 2 ways to speed it up:
1. collect stats without file scan. It may not collect all stats but good and fast enough for use case. HIVE-3917 addresses it
2. collect stats via partial file scan. It doesn't scan all content of files but part of it to get file metadata. some examples are https://cwiki.apache.org/Hive/rcfilecat.html for RCFile, ORC ( HIVE-3874 ) and HFile of Hbase
This jira is targeted to address the #2. More specifically RCFile format.
> support partial scan for analyze command - RCFile
> -------------------------------------------------
>
> Key: HIVE-3958
> URL: https://issues.apache.org/jira/browse/HIVE-3958
> Project: Hive
> Issue Type: Improvement
> Reporter: Gang Tim Liu
> Assignee: Gang Tim Liu
> Fix For: 0.11.0
>
> Attachments: HIVE-3958.patch.1, HIVE-3958.patch.2, HIVE-3958.patch.3, HIVE-3958.patch.4, HIVE-3958.patch.5, HIVE-3958.patch.6
>
>
> analyze commands allows us to collect statistics on existing tables/partitions. It works great but might be slow since it scans all files.
> There are 2 ways to speed it up:
> 1. collect stats without file scan. It may not collect all stats but good and fast enough for use case. HIVE-3917 addresses it
> 2. collect stats via partial file scan. It doesn't scan all content of files but part of it to get file metadata. some examples are https://cwiki.apache.org/Hive/rcfilecat.html for RCFile, ORC ( HIVE-3874 ) and HFile of Hbase (Edit: That link should be https://cwiki.apache.org/confluence/display/Hive/RCFileCat.)
> This jira is targeted to address the #2. More specifically RCFile format.
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