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https://issues.apache.org/jira/browse/TRAFODION-25?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14944241#comment-14944241
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ASF GitHub Bot commented on TRAFODION-25:
-----------------------------------------
Github user sureshsubbiah commented on a diff in the pull request:
https://github.com/apache/incubator-trafodion/pull/102#discussion_r41210672
--- Diff: core/sql/optimizer/BindRelExpr.cpp ---
@@ -11046,6 +11046,14 @@ RelExpr *MergeDelete::bindNode(BindWA *bindWA)
bindWA->setErrStatus();
return this;
}
+ if (CmpCommon::getDefault(COMP_BOOL_175) == DF_OFF)
--- End diff --
Does the optimizer fail to produce a plan with this change or even before?
Maybe a JIRA or a comment stating the failing DELETE+INSERT merge queries will
be useful. We may discussed this in the dev thread before, but is it possible
that UPDATE+INSERT could have a similar issue? UPDATE+INSERT MERGE statements
are now used more than before since any UPSERT statement with INDEX gets
transformed to them.
> Insert, delete and update operators should use specialized cost method
> -----------------------------------------------------------------------
>
> Key: TRAFODION-25
> URL: https://issues.apache.org/jira/browse/TRAFODION-25
> Project: Apache Trafodion
> Issue Type: Bug
> Reporter: Qifan Chen
> Assignee: David Wayne Birdsall
> Labels: performance
>
> In Trafodion, insert, delete and update operators do not use a specialized
> cost method that model the true operation involved.
> As a result, these operators can be assigned a zero cost and the query plan
> may not be optimal. In one example, a delete query against a partitioned
> table may get a serial plan.
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