HIVE-29578: Iceberg: add support for native views

[difin]

What changes were proposed in this pull request?

Added support for Iceberg native views in Hive for both HMS and REST catalogs.

There is a limitation in the current implementation: when Hive uses a REST catalog and creates a view on a partitioned Iceberg table, querying the view only works with CBO disabled. To be addressed in a follow-up PR.

Why are the changes needed?

To support Iceberg native views. This can be especially useful for REST Catalog clients.

Does this PR introduce any user-facing change?

Yes, new HQL syntax:

create view <view_name> as select * from <src_tbl> stored by iceberg;

How was this patch tested?

Created new and updated exiting unit and integration tests with Iceberg native views test cases.

[sonarqubecloud]

Quality Gate passed

Issues
27 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
3.4% Duplication on New Code

See analysis details on SonarQube Cloud

[kasakrisz]

IMHO think the syntax should follow materialized view syntax

hive/iceberg/iceberg-handler/src/test/queries/positive/mv_iceberg_orc2.q

Lines 16 to 17 in ee6848d

	create materialized view mat1 stored by iceberg stored as orc tblproperties ('format-version'='1') as
	select tbl_ice.b, tbl_ice.c from tbl_ice where tbl_ice.c > 52;

I checked some other database engines (Trino, Dremio) that supports Iceberg logical views, none of them adds extra keywords to the SQL syntax but they enable define the catalog where the view should be stored and that catalog should be Iceberg

[kasakrisz]

The keywords STORED BY ICEBERG are a bit confusing because no data is actually stored in the case of logical views. Some engines do not require extra keywords to specify when creating Iceberg logical views.

If we insist on using keywords, how about something like these?

create view <view_name> viewproperties(format='iceberg')
as select...;

create view <view_name> format iceberg
as select...;

If we decide to go with the STORED BY ICEBERG keywords, please create a new grammar rule specifically for views—similar to tableFileFormat—called viewMetadataFormat. This should limit the grammar to the STORED BY <identifier> syntax. By doing this, you can eliminate the need for extra validation checks in the analyzer.

I recommend checking the configuration setting hive.default.storage.handler.class when deciding where to store the view metadata. If a storage handler is set that supports views, let's use the Storage Handler API to store the metadata.