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https://issues.apache.org/jira/browse/TRAFODION-2322?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15613241#comment-15613241
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David Wayne Birdsall commented on TRAFODION-2322:
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The problem has been traced to string columns. Trafodion treats these as
VARCHAR(31999) columns. When processing these columns, it treats them as if
they were 32K long even though they typically are just a few bytes long. The
extra memory allocated and extra data movement kills performance.
> UPDATE STATS for ORC TPC-H Lineitem table takes much longer now
> ---------------------------------------------------------------
>
> Key: TRAFODION-2322
> URL: https://issues.apache.org/jira/browse/TRAFODION-2322
> Project: Apache Trafodion
> Issue Type: Bug
> Components: sql-cmp
> Affects Versions: 2.0-incubating
> Environment: All
> Reporter: David Wayne Birdsall
> Assignee: David Wayne Birdsall
>
> When using a LINEITEM table with about 12 million rows, and storing that
> LINEITEM table in Hive ORC files, UPDATE STATISTICS has regressed in its
> performance. On one test system, the elapsed time changed from 6 minutes 20
> seconds to 31 minutes 31 seconds.
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