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https://issues.apache.org/jira/browse/IGNITE-8047?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vladimir Ozerov updated IGNITE-8047:
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Description:
{{SELECT COUNT(DISTINCT <expr>) FROM table}} will fetch full data set to reduce
node.
Looks like we can add group by '<expr>'- push down DISTINCT into map query to
reduce network pressure.
See details on nabble [1].
[1]
[http://apache-ignite-users.70518.x6.nabble.com/COUNT-DISTINCT-could-push-down-group-expressions-tt20782.html]
was:
"Select COUNT(DISTINCT <expr>) From table;" will fetch full data set to reduce
node.
Looks like we can add group by '<expr>'- push down DISTINCT into map query to
reduce network pressure.
See details on nabble [1].
[1]
[http://apache-ignite-users.70518.x6.nabble.com/COUNT-DISTINCT-could-push-down-group-expressions-tt20782.html]
> SQL: optimize simple COUNT with DISTINCT query.
> -----------------------------------------------
>
> Key: IGNITE-8047
> URL: https://issues.apache.org/jira/browse/IGNITE-8047
> Project: Ignite
> Issue Type: Improvement
> Components: sql
> Reporter: Andrew Mashenkov
> Assignee: Vladimir Ozerov
> Priority: Major
> Labels: performance
>
> {{SELECT COUNT(DISTINCT <expr>) FROM table}} will fetch full data set to
> reduce node.
> Looks like we can add group by '<expr>'- push down DISTINCT into map query to
> reduce network pressure.
> See details on nabble [1].
> [1]
> [http://apache-ignite-users.70518.x6.nabble.com/COUNT-DISTINCT-could-push-down-group-expressions-tt20782.html]
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