Materialize table_types_internal as CTE in sys.all_objects to prevent view inlining

[RuchaSK1]

Description

The sys.all_objects view joins against sys.table_types_internal to exclude table types from the user table branches. Because table_types_internal is a plain view, the planner inlines its definition (a 4-way join across pg_type, pg_namespace, pg_class, pg_depend) and re-executes it per row inside a nested loop, causing significant performance degradation.

This change wraps table_types_internal in a materialized CTE inside sys.all_objects so it is computed once and reused.

We observed following performance improvement:

With enable_mergejoin = on (default):

Query	Before Fix	After Fix	Improvement
SELECT OBJECTPROPERTYEX(286596, 'IsSchemaBound')	10s	1.58s	6×
SELECT COUNT(*) FROM sys.all_objects	6min 33s	1.72s	247×
SELECT OBJECTPROPERTYEX(34290, 'BaseType')	11s	1.56s	7×
Full SSMS view enumeration query	4min 38s	23.49s	12×

With enable_mergejoin = off:

Query	Before Fix	After Fix	Improvement
SELECT OBJECTPROPERTYEX(286596, 'IsSchemaBound')	6min 25s	1.58s	244×
SELECT COUNT(*) FROM sys.all_objects	6min 28s	1.72s	244×
SELECT OBJECTPROPERTYEX(34290, 'BaseType')	6min 28s	1.55s	251×
Full SSMS view enumeration query	3hr 15min	23.9s	452×

Issues Resolved

Task: BABEL-6404

Authored-by: Rucha Kulkarni ruchask@amazon.com
Signed-off-by: Rucha Kulkarni ruchask@amazon.com

Test Scenarios Covered

• Use case based - Yes

• Boundary conditions -

• Arbitrary inputs -

• Negative test cases -

• Minor version upgrade tests -

• Major version upgrade tests -

• Performance tests -

• Tooling impact -

• Client tests -

Check List

• Commits are signed per the DCO using --signoff

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[KushaalShroff]

LGTM! Please add perf numbers in description