[
https://issues.apache.org/jira/browse/CALCITE-3746?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17018796#comment-17018796
]
pengzhiwei commented on CALCITE-3746:
-------------------------------------
Hi [~vladimirsitnikov]，the expression "a is not null and f(a)" compute "a is
not null" first. If a is not null, then compute "f(a)",.It cannot avoid NPE in
"f(a)".Howerver, after the optimization,"f(a)"
execute first.This will throw NPE in "f(a)" if "f" cannot deal with the case "a
= null".
> RexSimplify changes the order of IS NOT NULL in And RexNode
> -----------------------------------------------------------
>
> Key: CALCITE-3746
> URL: https://issues.apache.org/jira/browse/CALCITE-3746
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.20.0
> Reporter: pengzhiwei
> Assignee: pengzhiwei
> Priority: Major
> Labels: pull-request-available
> Time Spent: 10m
> Remaining Estimate: 0h
>
> The RexSimplify changes the order of IS NOT NULL in And RexNode.The following
> expression
> {code:java}
> a is not null and length(a) > 0{code}
> is optimazted to
> {code:java}
> length(a) > 0 and a is not null{code}
> which will affect the logic short circuit for null-test.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
