tree 529d584e38aca3e9e84968b1626b92c41c963c58
parent fcf8aa59b5025dde9b4af36953146894659967e2
author Terry Kim <yuminkim@gmail.com> 1603863895 +0000
committer Wenchen Fan <wenchen@databricks.com> 1603863895 +0000

[SPARK-33174][SQL] Migrate DROP TABLE to use UnresolvedTableOrView to resolve the identifier

### What changes were proposed in this pull request?

This PR proposes to migrate `DROP TABLE` to use `UnresolvedTableOrView` to resolve the table/view identifier. This allows consistent resolution rules (temp view first, etc.) to be applied for both v1/v2 commands. More info about the consistent resolution rule proposal can be found in [JIRA](https://issues.apache.org/jira/browse/SPARK-29900) or [proposal doc](https://docs.google.com/document/d/1hvLjGA8y_W_hhilpngXVub1Ebv8RsMap986nENCFnrg/edit?usp=sharing).

### Why are the changes needed?

The current behavior is not consistent between v1 and v2 commands when resolving a temp view.
In v2, the `t` in the following example is resolved to a table:
```scala
sql("CREATE TABLE testcat.ns.t (id bigint) USING foo")
sql("CREATE TEMPORARY VIEW t AS SELECT 2")
sql("USE testcat.ns")
sql("DROP TABLE t") // 't' is resolved to testcat.ns.t
```
whereas in v1, the `t` is resolved to a temp view:
```scala
sql("CREATE DATABASE test")
sql("CREATE TABLE spark_catalog.test.t (id bigint) USING csv")
sql("CREATE TEMPORARY VIEW t AS SELECT 2")
sql("USE spark_catalog.test")
sql("DROP TABLE t") // 't' is resolved to a temp view
```

### Does this PR introduce _any_ user-facing change?

After this PR, for v2, `DROP TABLE t` is resolved to a temp view `t` instead of `testcat.ns.t`, consistent with v1 behavior.

### How was this patch tested?

Added a new test

Closes #30079 from imback82/drop_table_consistent.

Authored-by: Terry Kim <yuminkim@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>