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https://issues.apache.org/jira/browse/CALCITE-3769?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17033365#comment-17033365
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Danny Chen commented on CALCITE-3769:
-------------------------------------
[~vladimirsitnikov] This fix does not expect to break the plans for engines
that use Calcite as a dependency lib, because the Enumerations is just a
physical implementations for Calcite itself.
One thing i can think of is after this patch, the RelBuilder#scan now always do
table expanding(e.g. call RelOptTable#toRel), but i think this is not a
problem, because based on the document of method RelOptTable#toRel, it should
always return a logical node for the table, and we should always expand the
table sooner or later in the planning.
In SqlToRelConverter#Config, an config option isConvertTableAccess controls if
the RelOptTable#toRel should be invoked, from the comment, it seems that
RelStructuredTypeFlattener relies on the no expanding logical nodes to do some
conversion, but with this fix, i think this config option should be deprecated
and always return "true".
> Deprecate TableScanRule
> -----------------------
>
> Key: CALCITE-3769
> URL: https://issues.apache.org/jira/browse/CALCITE-3769
> Project: Calcite
> Issue Type: Wish
> Components: core
> Affects Versions: 1.21.0
> Reporter: Danny Chen
> Assignee: Danny Chen
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.22.0
>
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> The TableScanRule is the only planner rule that for a logical node(e.g. the
> table scan), its function is to pass along the cluster object and invoke the
> RelOptTable#toRel which is very trivial because it supplies only a simple
> ToRelContext that does not support expanding view/passing table hints.
> For rels that come from the sql-to-rel conversion, there is already a table
> conversion logic[1]. This code gives a more powerful ToRelContext that has
> the complete functionality.
> The only reason that I saw the meaning of existing TableScanRule is for the
> TableScan that comes from the RelBuilder#scan.
> So I would suggest to deprecate the TableScanRule, instead, we support
> translating the table directly in RelBuilder#scan,
> We also add a new interface RelBuilder#scan(Iterable<String> tableNames,
> ToRelContext context), so that user can pass in a more powerful ToRelContext
> explicitly.
> [1]
> https://github.com/apache/calcite/blob/d6fa25cd11625ad7b4b74dafbd0211c701b38d49/core/src/main/java/org/apache/calcite/sql2rel/SqlToRelConverter.java#L3498
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