metadata column support

[chenkovsky]

Is your feature request related to a problem or challenge?

spark support metadata column

https://spark.apache.org/docs/3.4.3/api/java/org/apache/spark/sql/connector/catalog/SupportsMetadataColumns.html

then we can treat rowid as metadata column.

Describe the solution you'd like

add metadata column in TableProvider trait

Describe alternatives you've considered

No response

Additional context

No response

[nishikinocurtis]

+1, also encountering cases where parsing and executing queries referring to rowid is required.

Both logical planning and physical planning (related to scan()s) would also need enhancement to 1. parse queries refer to metadata columns and 2. if necessary produce corresponding execution plan to pull metadata out.

I'd be interested in contributing this feature if more detailed discussion regarding these surrounding implementation is made.

[alamb]

@nishikinocurtis -- perhaps you can look at the proposed PR / API here:

• feat: metadata columns #14057

[alamb]

I think this is duplicated by #15173 so let's continue the discussion there