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https://issues.apache.org/jira/browse/CALCITE-7041?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17953939#comment-17953939
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Julian Hyde commented on CALCITE-7041:
--------------------------------------
Which component do you think should do this simplification? Several components,
including RelBuilder and RexSimplify, already do these kinds of things.
Some simplifications are straightforward to humans but have to consider all
orderings of terms, which is O(n!) in a conjunction of n terms. We can do such
simplifications once per query, but we can't do them on every rule-firing.
> Simplify simple contradicting expressions
> -----------------------------------------
>
> Key: CALCITE-7041
> URL: https://issues.apache.org/jira/browse/CALCITE-7041
> Project: Calcite
> Issue Type: Improvement
> Reporter: Sergey Nuyanzin
> Priority: Major
>
> For instance
> {code:sql}
> a > b AND b > a AND a IS NOT NULL AND b IS NOT NULL
> {code}
> or
> {code:sql}
> a >= b AND b > a AND a IS NOT NULL AND b IS NOT NULL
> {code}
> or
> {code:sql}
> a > b AND b >= a AND a IS NOT NULL AND b IS NOT NULL
> {code}
> could be simplified to {{FALSE}}
> and
> {code:sql}
> a >= b AND b >= a AND a IS NOT NULL AND b IS NOT NULL
> {code}
> could be simplified to {{a = b}}
> Probably there is something else
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