[
https://issues.apache.org/jira/browse/CALCITE-4562?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17314001#comment-17314001
]
Julian Hyde commented on CALCITE-4562:
--------------------------------------
I've already started work on it, and in fact am almost ready to commit; see
[5ddb7dc8|https://github.com/julianhyde/calcite/commit/5ddb7dc808986ecf46c0a7e5a38896f8b499ba00].
Sorry I didn't "start progress".
> Improve simplification of "expression IS TRUE"
> ----------------------------------------------
>
> Key: CALCITE-4562
> URL: https://issues.apache.org/jira/browse/CALCITE-4562
> Project: Calcite
> Issue Type: Bug
> Reporter: Julian Hyde
> Assignee: Julian Hyde
> Priority: Major
>
> When simplifying "expression IS TRUE", RexSimplify should simplify
> "expression" in an "unknown as FALSE" context, and this should allow more
> simplifications than at present.
> Currently "(x LIKE '%') IS TRUE" simplifies to "(x IS NOT NULL) IS TRUE", but
> after this change will simplify to "x IS NOT NULL". The following test
> illustrates:
> {code}
> final RexNode ref = input(tVarchar(true, 10), 0);
> checkSimplify(isTrue(like(ref, literal("%"))), "IS NOT NULL($0)");
> {code}
> Similarly "IS FALSE", "IS NOT TRUE", etc.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
