[
https://issues.apache.org/jira/browse/CALCITE-2454?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16741797#comment-16741797
]
Vladimir Sitnikov commented on CALCITE-2454:
--------------------------------------------
{quote}Can you clarify: when you omit charset and collation, are you using the
SESSION defaults or the GLOBAL default? It's important that you use the GLOBAL
default, because may need to compare digests that are created in sessions that
have different default charsets.{quote}
I believe I use GLOBAL: {{SqlCollation.IMPLICIT.getCharset()}}
I can update to {{SaffronProperties.INSTANCE.defaultCollation().get()}} if you
think that is better.
> HepPlanner should not pick cached RelNode when type mismatch while digest
> matches
> ---------------------------------------------------------------------------------
>
> Key: CALCITE-2454
> URL: https://issues.apache.org/jira/browse/CALCITE-2454
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.17.0
> Reporter: Yuzhao Chen
> Assignee: Julian Hyde
> Priority: Major
> Labels: pull-request-available
> Attachments: expr_types.png, project_with_literals_digest.png
>
>
> After CALCITE-2116, a RelNode will be reused based on digest, but now many
> nodes's digests do not have type info, e.g. LogicalProject, this will affect
> some rules when we wanna transform to a node with same digest and same type
> (HepPlanner may pick out a RelNode with different type).
> So, we should add type info just like VolcanoPlanner.
> We encounter this problem with plan like below:
> {code:java}
> Union
> +-- project1(a: int, b:int, c: double)
> | +-- project2(a: bigint: b: int, c:double)
> +-- project3
> {code}
> We wanna cast a from bigint -> int so we can have a union with project1 and
> project3, but with ProjectMergeRule, while merging project1 and project2,
> HepPlanner will think project2 and project1 are identical and it gives back
> project2. But actually we wanna pick project1.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
