[SPARK-14125] [SQL] Native DDL Support: Alter View

[gatorsmile]

What changes were proposed in this pull request?

This PR is to provide a native DDL support for the following three Alter View commands:

Based on the Hive DDL document:
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL

1. ALTER VIEW RENAME

Syntax:

ALTER VIEW view_name RENAME TO new_view_name

• to change the name of a view to a different name
• not allowed to rename a view's name by ALTER TABLE

2. ALTER VIEW SET TBLPROPERTIES

Syntax:

ALTER VIEW view_name SET TBLPROPERTIES ('comment' = new_comment);

• to add metadata to a view
• not allowed to set views' properties by ALTER TABLE
• ignore it if trying to set a view's existing property key when the value is the same
• overwrite the value if trying to set a view's existing key to a different value

3. ALTER VIEW UNSET TBLPROPERTIES

Syntax:

ALTER VIEW view_name UNSET TBLPROPERTIES [IF EXISTS] ('comment', 'key')

• to remove metadata from a view
• not allowed to unset views' properties by ALTER TABLE
• issue an exception if trying to unset a view's non-existent key

How was this patch tested?

Added test cases to verify if it works properly.

[SparkQA]

Test build #55595 has finished for PR 12324 at commit cd20636.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[gatorsmile]

cc @yhuai @andrewor14

[andrewor14]

nit: I left this line intentionally!

[gatorsmile]

Ok, I see.

[andrewor14]

Looks great! Only minor comments.

[SparkQA]

Test build #55782 has finished for PR 12324 at commit e82aa47.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

withView will help us drop the view at last.

[gatorsmile]

Sure, remove it now. Thanks!

[cloud-fan]

LGTM except some minor comments

[SparkQA]

Test build #55815 has finished for PR 12324 at commit db7f931.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[yhuai]

Thanks. Merging to master.