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https://issues.apache.org/jira/browse/CALCITE-2454?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16740733#comment-16740733
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Vladimir Sitnikov commented on CALCITE-2454:
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I suggest the following:
1) trim "boolean not null" for true/false literals
2) trim "integer not null" for integer literal
3) somehow avoid printing datatypes for rexliterals inside Values in case type
matches column type.
Consider an expression: {{cast( (2+3) as integer)}}
Current digest does not tell us the types of 2 and 3.
Adding RowType to the cache key does not solve the problem as well, since
overall type is INTEGER (after the cast), and we truly need to distinguish
between {{cast( (2:int+3:int) as integer)}} and {{cast( (2:double+3:double)
as integer)}} since the results might be different.
> 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: 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.
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