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https://issues.apache.org/jira/browse/TRAFODION-1914?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15289075#comment-15289075
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liu ming commented on TRAFODION-1914:
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Hi, Eric,
I filed JIRA 1976
Trafodion support to create 'unique index'. In that case, one should make sure
the index column value will be unique. Then that index will not have primary
key list into clustering key.
This is already supported but not documented.
So this seems like a solved issue?
> optimize "added columns" in indexes
> -----------------------------------
>
> Key: TRAFODION-1914
> URL: https://issues.apache.org/jira/browse/TRAFODION-1914
> Project: Apache Trafodion
> Issue Type: Improvement
> Components: sql-cmp
> Reporter: Eric Owhadi
>
> the current CREATE INDEX feature will always put each column added to the
> index in the clustering key. But sometimes, users just want to add columns to
> the index to avoid having to probe back the primary table to fetch just one
> or 2 column back. Instead copying these columns in the index can avoid making
> a probe back to main table and therefore improve performance. Current
> implementation allows this, but will always put the extra column as part of
> the clustering key. That is not optimal, and very bad for the case of
> VARCHAR, since they are exploded to there max size when part of the
> clustering key. So this JIRA is abount altering the syntax of create index,
> and flag columns that are added but should not be part of the clustering key.
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