Stamatis Zampetakis created CALCITE-7059:
--------------------------------------------
Summary: Generalize RelFieldTrimmer to handle plans with arbitrary
operators
Key: CALCITE-7059
URL: https://issues.apache.org/jira/browse/CALCITE-7059
Project: Calcite
Issue Type: Improvement
Components: core
Affects Versions: 1.40.0
Reporter: Stamatis Zampetakis
Currently the
[RelFieldTrimmer|https://github.com/apache/calcite/blob/597b1fd54fe5b8586525aed2bc4518ca54a25523/core/src/main/java/org/apache/calcite/sql2rel/RelFieldTrimmer.java]
class is mostly tailored to handle plans using the built-in {{LogicalXx}}
operators. Still there are many projects that have their own flavor of
"logical" operators, which do not differ much from the built-in when it comes
to field trimming, and are forced to extend or copy the trimmer code in order
to use it.
To further expand the usage of the trimmer and minimize unnecessary extensions
we could envision the following enhancements.
*Refactor references/usages of LogicalXx operators*
In most cases a {{Logical}} operator is extending another more abstract one so
we could favor the use of the abstract one in every place where a logical one
is used.
*Use {{RelNode#copy}} instead of the {{RelBuilder}} to create the new (trimmed)
expressions*
The trimmer currently makes use of a {{RelBuilder}} in various places to create
the new operators. There are advantages in using the RelBuilder but when plans
mix operators from different conventions (e.g., Enumerable and Jdbc) the
builder and subsequently the trimmer cannot be used; the old and the new
(trimmed) operator must be in the same convention.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
