SQLAlchemy test cases that hang using the Ingres dialect

[hab6]

Several tests in the SQLAlchemy test suite hang when using the Ingres dialect. Prior to merging PR #42, some of these tests were failing with: ERROR: No value specified for mandatory column 'id'

Tests known to hang with the Ingres dialect against Ingres 11.2:

• VersioningTest::test_save_update - test\orm\inheritance\test_basic.py
• PartialFlushTest::test_o2m_m2o - test\orm\test_cascade.py
• MapperEventsTest::test_merge - test\orm\test_events.py
• SessionTransactionTest::test_transactions_isolated - test\orm\test_transaction.py
• AlternateGeneratorTest::test_child_row_switch_two - test\orm\test_versioning.py

Initial investigation should include:

• Running the same tests with at least one other dialect to compare behavior.
• Reducing the problem to one or more simple tests that run apart from the SQLAlchemy test suite.

[hab6]

Each of the tests that hang with the Ingres dialect and an Ingres 11.2 database will pass if using the PostgreSQL dialect with a PostgreSQL 16.2 database.

Test	Result with Ingres 11.2	Result with PostgreSQL 16.2
test/orm/inheritance/test_basic.py VersioningTest::test_save_update	HANG	PASS
test/orm/test_cascade.py PartialFlushTest::test_o2m_m2o	HANG	PASS
test/orm/test_events.py MapperEventsTest::test_merge	HANG	PASS
test/orm/test_transaction.py SessionTransactionTest::test_transactions_isolated	HANG	PASS
test/orm/test_versioning.py AlternateGeneratorTest::test_child_row_switch_two	HANG	PASS

[hab6]

Brief research notes:

The attached file (test_basic_hang.py.txt) is a test that hangs when using the Ingres dialect v0.0.7.dev1 yet does not hang with either the Postgres dialect or the SQLite dialect. In the given test, the hang occurs on the second commit when using the Ingres dialect.

Digging a little deeper shows the hang occurs in file sqlalchemy\lib\sqlalchemy\engine\base.py, class method Connection::exec_single_context() at line 1971 (of SQLAlchemy v2.0.29.dev0) on the call to self.dialect.do_execute().

[clach04]

@hab6 what does ipm/iimonitor show? More than 1 session?

[hab6]

Internal ticket II-14071