Previously, the information_schema.triggers table was unimplemented
and always returned zero rows. This made it impossible to query
trigger metadata through standard SQL information schema views.

This change implements the populate function for information_schema.triggers,
allowing users to query trigger information. The implementation:

Note that transition tables (action_reference_old_table/new_table) will
only be populated once statement-level triggers are supported. Currently,
these columns return NULL for row-level triggers.

Fixes cockroachdb#143534

Release note (sql change): The information_schema.triggers table is now
populated with trigger metadata. Users can query this table to see all
triggers defined in their database, including the trigger name, timing
(BEFORE/AFTER), event type (INSERT/UPDATE/DELETE), and associated function.
Each trigger event appears as a separate row in the table.

147087: xform: increase pool size for "heavy" configs r=yuzefovich a=yuzefovich

We just saw an engflow failure that looks like an OOM under deadlock config, so let's bump the size.

Fixes: #146867.

Release note: None

147182: row/fetcher: clean up and harden TestRowFetcherMVCCMetadata r=yuzefovich a=yuzefovich

This commit refactors `TestRowFetcherMVCCMetadata` a bit to explicitly request `crdb_internal_mvcc_timestamp` as opposed to fishing it out of the fetcher, which allows removing an exported method from the latter.

This commit also hardens the test to de-flake it when write buffering is enabled. The test scans the storage engine directly, so we need to tweak a testing knob to ensure that COMMIT blocks until the writes are committed into pebble.

Fixes: #147174.

Release note: None

147237: sql: populate information_schema.triggers r=rafiss a=rafiss

Previously, the information_schema.triggers table was unimplemented and always returned zero rows. This made it impossible to query trigger metadata through standard SQL information schema views.

This change implements the populate function for information_schema.triggers, allowing users to query trigger information. The implementation:

Note that transition tables (action_reference_old_table/new_table) will only be populated once statement-level triggers are supported. Currently, these columns return NULL for row-level triggers.

Fixes #143534

Release note (sql change): The information_schema.triggers table is now populated with trigger metadata. Users can query this table to see all triggers defined in their database, including the trigger name, timing (BEFORE/AFTER), event type (INSERT/UPDATE/DELETE), and associated function. Each trigger event appears as a separate row in the table.

Co-authored-by: Yahor Yuzefovich <[email protected]>
Co-authored-by: Rafi Shamim <[email protected]>

This commit populates the pg_catalog.pg_trigger virtual table,
which provides metadata about database triggers.

The implementation includes:
- Correct calculation of the tgtype bitmap field according to PostgreSQL's
specification, where bits represent:
 - Bit 0: FOR EACH ROW (1) or FOR EACH STATEMENT (0)
 - Bit 1: BEFORE timing
 - Bits 2-4: Event types (INSERT=4, DELETE=8, UPDATE=16)
 - Bit 5: TRUNCATE (32) - reserved for future use
 - Bit 6: INSTEAD OF (64) - reserved for future use
- Support for trigger function arguments stored in tgargs as a null-separated
  bytea array.
- WHEN clause conditions stored in tgqual

The tgenabled field always returns 'A' (always enabled) as CockroachDB does
not yet support trigger enable/disable states.

Tests are added to verify the pg_trigger contents, including the tgtype
bitmap calculation and triggers with function arguments.

Fixes cockroachdb#143534

Release note (sql change): The pg_catalog.pg_trigger table now
returns metadata about database triggers.

This commit populates the pg_catalog.pg_trigger virtual table,
which provides metadata about database triggers.

The implementation includes:
- Correct calculation of the tgtype bitmap field according to PostgreSQL's
specification, where bits represent:
 - Bit 0: FOR EACH ROW (1) or FOR EACH STATEMENT (0)
 - Bit 1: BEFORE timing
 - Bits 2-4: Event types (INSERT=4, DELETE=8, UPDATE=16)
 - Bit 5: TRUNCATE (32) - reserved for future use
 - Bit 6: INSTEAD OF (64) - reserved for future use
- Support for trigger function arguments stored in tgargs as a null-separated
  bytea array.
- WHEN clause conditions stored in tgqual

The tgenabled field always returns 'A' (always enabled) as CockroachDB does
not yet support trigger enable/disable states.

Tests are added to verify the pg_trigger contents, including the tgtype
bitmap calculation and triggers with function arguments.

Fixes cockroachdb#143534

Release note (sql change): The pg_catalog.pg_trigger table now
returns metadata about database triggers.

Previously, the information_schema.triggers table was unimplemented
and always returned zero rows. This made it impossible to query
trigger metadata through standard SQL information schema views.

This change implements the populate function for information_schema.triggers,
allowing users to query trigger information. The implementation:

Note that transition tables (action_reference_old_table/new_table) will
only be populated once statement-level triggers are supported. Currently,
these columns return NULL for row-level triggers.

Fixes cockroachdb#143534

Release note (sql change): The information_schema.triggers table is now
populated with trigger metadata. Users can query this table to see all
triggers defined in their database, including the trigger name, timing
(BEFORE/AFTER), event type (INSERT/UPDATE/DELETE), and associated function.
Each trigger event appears as a separate row in the table.

This commit populates the pg_catalog.pg_trigger virtual table,
which provides metadata about database triggers.

The implementation includes:
- Correct calculation of the tgtype bitmap field according to PostgreSQL's
specification, where bits represent:
 - Bit 0: FOR EACH ROW (1) or FOR EACH STATEMENT (0)
 - Bit 1: BEFORE timing
 - Bits 2-4: Event types (INSERT=4, DELETE=8, UPDATE=16)
 - Bit 5: TRUNCATE (32) - reserved for future use
 - Bit 6: INSTEAD OF (64) - reserved for future use
- Support for trigger function arguments stored in tgargs as a null-separated
  bytea array.
- WHEN clause conditions stored in tgqual

The tgenabled field always returns 'A' (always enabled) as CockroachDB does
not yet support trigger enable/disable states.

Tests are added to verify the pg_trigger contents, including the tgtype
bitmap calculation and triggers with function arguments.

Fixes cockroachdb#143534

Release note (sql change): The pg_catalog.pg_trigger table now
returns metadata about database triggers.

This commit populates the pg_catalog.pg_trigger virtual table,
which provides metadata about database triggers.

The implementation includes:
- Correct calculation of the tgtype bitmap field according to PostgreSQL's
specification, where bits represent:
 - Bit 0: FOR EACH ROW (1) or FOR EACH STATEMENT (0)
 - Bit 1: BEFORE timing
 - Bits 2-4: Event types (INSERT=4, DELETE=8, UPDATE=16)
 - Bit 5: TRUNCATE (32) - reserved for future use
 - Bit 6: INSTEAD OF (64) - reserved for future use
- Support for trigger function arguments stored in tgargs as a null-separated
  bytea array.
- WHEN clause conditions stored in tgqual

The tgenabled field always returns 'A' (always enabled) as CockroachDB does
not yet support trigger enable/disable states.

Tests are added to verify the pg_trigger contents, including the tgtype
bitmap calculation and triggers with function arguments.

Fixes cockroachdb#143534

Release note (sql change): The pg_catalog.pg_trigger table now
returns metadata about database triggers.

147248: sql: populate pg_catalog.pg_trigger r=rafiss a=rafiss

This commit populates the pg_catalog.pg_trigger virtual table, which provides metadata about database triggers.

The implementation includes:
- Correct calculation of the tgtype bitmap field according to PostgreSQL's specification, where bits represent:
  - Bit 0: FOR EACH ROW (1) or FOR EACH STATEMENT (0)
  - Bit 1: BEFORE timing
  - Bits 2-4: Event types (INSERT=4, DELETE=8, UPDATE=16)
  - Bit 5: TRUNCATE (32) - reserved for future use
  - Bit 6: INSTEAD OF (64) - reserved for future use
- Support for trigger function arguments stored in tgargs as a null-separated bytea array.
- WHEN clause conditions stored in tgqual

The tgenabled field always returns 'A' (always enabled) as CockroachDB does not yet support trigger enable/disable states.

Tests are added to verify the pg_trigger contents, including the tgtype bitmap calculation and triggers with function arguments.

informs #143534
Epic: CRDB-42942

Release note (sql change): The pg_catalog.pg_trigger table now returns metadata about database triggers.

Co-authored-by: Rafi Shamim <[email protected]>