[
https://issues.apache.org/jira/browse/CALCITE-1488?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Julian Hyde resolved CALCITE-1488.
----------------------------------
Resolution: Fixed
Fix Version/s: 1.11.0
[~gian], Your analysis of the problem is correct, and your proposed fix would
have worked. However, since we already have rules for "propagating emptiness"
(in {{PruneEmptyRules}}), the simplest thing is to have {{ValuesReduceRule}}
back off and let those rules do their job. (After all, if you have a filter or
project on top of an empty relation, it's a waste of effort to simplify the
filter or project, because you know the result is going to be empty.) So that's
what I have done.
Fixed in http://git-wip-us.apache.org/repos/asf/calcite/commit/f36584ab.
You will need to enable {{PruneEmptyRules.PROJECT_INSTANCE}}, if you haven't
already.
> ValuesReduceRule should ignore empty Values
> -------------------------------------------
>
> Key: CALCITE-1488
> URL: https://issues.apache.org/jira/browse/CALCITE-1488
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.10.0
> Reporter: Gian Merlino
> Assignee: Julian Hyde
> Fix For: 1.11.0
>
>
> ValuesReduceRule doesn't propagate rowType on Project of empty Values. If
> ValuesReduceRule is trying to reduce a Project on top of an empty Values,
> then changeCount ends up 0, and it returns the underlying Values. This leads
> to an assertion failure because the returned Values does not have the
> expected rowType.
> One way to fix this is changing the "Filter had no effect" logic from
> "{{changeCount == 0}}" to "{{changeCount == 0 && projectExprs == null}}".
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
