cloud-fan commented on issue #25747: [SPARK-29039][SQL] centralize the catalog 
and table lookup logic
URL: https://github.com/apache/spark/pull/25747#issuecomment-535757609
 
 
   Hi @rdblue , thanks for your suggestion in 
https://github.com/apache/spark/pull/25747#discussion_r328844941
   
   I think it works, but then we need to look up catalog twice: once for 
determine whether it's a v2 catalog, once to resolve the `UnresolvedRelation`. 
It also introduces duplicated code if we support v2 tables in session catalog 
later.
   
   But this inspires me with a new idea. Instead of keeping a `Seq[String]` in 
the statement plan, we can keep a `UnresolvedV2Table(tableName: Seq[String], 
catalog: Option[TableCatalog])`. Then we can have a rule to resolve catalog and 
set the `UnresolvedV2Table.catalog`, and another rule to resolve 
`UnresolvedV2Table` to `DataSourceV2Relation`.
   
   I'll push a commit to implement this idea soon.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
[email protected]


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to