[jira] [Created] (SPARK-16374) Remove Alias from MetastoreRelation and SimpleCatalogRelation

["Xiao Li (JIRA)" <ji...@apache.org>]

Xiao Li created SPARK-16374:
-------------------------------

             Summary: Remove Alias from MetastoreRelation and SimpleCatalogRelation
                 Key: SPARK-16374
                 URL: https://issues.apache.org/jira/browse/SPARK-16374
             Project: Spark
          Issue Type: Improvement
          Components: SQL
    Affects Versions: 2.0.0
            Reporter: Xiao Li


Different from the other leaf nodes, `MetastoreRelation` and `SimpleCatalogRelation` have a pre-defined `alias`, which is used to change the qualifier of the node. However, based on the existing alias handling, alias should be put in `SubqueryAlias`. 

This PR is to separate alias handling from `MetastoreRelation` and `SimpleCatalogRelation` to make it consistent with the other nodes. 

For example, below is an example query for `MetastoreRelation`:
```SQL
SELECT tmp.a + 1 FROM test_parquet_ctas tmp WHERE tmp.a > 2
```

Before changes, the analyzed plan is
```
== Analyzed Logical Plan ==
(a + 1): int
Project [(a#951 + 1) AS (a + 1)#952]
+- Filter (a#951 > 2)
   +- SubqueryAlias tmp
      +- Relation[a#951] parquet
```
After changes, the analyzed plan becomes
```
== Analyzed Logical Plan ==
(a + 1): int
Project [(a#951 + 1) AS (a + 1)#952]
+- Filter (a#951 > 2)
   +- SubqueryAlias tmp
      +- SubqueryAlias test_parquet_ctas
         +- Relation[a#951] parquet
```

**Note: the optimized plans are the same.**

For `SimpleCatalogRelation`, the existing code always generates two Subqueries. Thus, no change is needed.




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org