Avoid running SQLAlchemy schema tests with Ingres dialect

[hab6]

When running the SQLAlchemy dialect compliance suite, quite a few tests would fail with some form of the following error:

sqlalchemy.exc.ProgrammingError: (pyodbc.ProgrammingError)
('42503', "[42503] [Actian][Actian II ODBC Driver][INGRES]
CREATE TABLE: You may not create an object owned by 'test_schema'. (328737) (SQLExecDirectW)")
[SQL:
CREATE TABLE test_schema.test_table (
    id INTEGER GENERATED BY DEFAULT AS IDENTITY NOT NULL,
    data VARCHAR(50),
    PRIMARY KEY (id) )

The reason for the error is that the affected tests attempt to create and drop tables owned under schemas different than the current user.

Ingres does not support this kind of operation except in rare instances where the current user has security administrator and operator privilege or who is the DBA of the database. The user must then use the SET SESSION AUTHORIZATION ... command to set the effective user for the current session.

Per discussion in 11366 and additional research in internal ticket II-14148, the setting supports_schemas = False will be added to the IngresDialect class to avoid execution of tests that use alternate schemas.

The file README.testsuite.md is being added to provide information on how to run the dialect compliance suite and also provide information about the issue of running tests that contain alternate schemas.

Testing

Ingres 11.2 (15807) on Windows 10 (client and server are same machine)
Python 3.10.7
mock 5.1.0
pluggy 1.5.0
psycopg2 2.9.9
pyodbc 5.1.0
pypyodbc 1.3.6
pytest 8.1.1
setuptools 69.5.1
SQLAlchemy 2.0.29.dev0
sqlalchemy-ingres 0.0.7.dev1
tox 4.14.2

Result	Baseline	With supports_schemas = False	Diff
Total Tests	1531	1531	-
Passed	336	473	+137
Failed	63	173	+110
Errors	798	30	-768
Skipped	334	855	+521
Run Time	17m 25s	42s	-16m 43s

[hab6]

I am suspicious about the huge jump in skipped tests when setting supports_schemas = False in the IngresDialect class.

Result	Without supports_schemas = False	With supports_schemas = False	Diff
Skipped	334	855	+521

I think it will be important to run the suite with and without the setting and review the 521 tests that are affected to see they are indeed skipped due to the alternate schema issue and not some side effect.

[clach04]

Looks good.

Needs explanation text (that you wrote in the PR ) in the readme.

Minor tweak suggested for quoting.

[clach04]

quote this, i.e. prefix with >

[clach04]

quote these too, makes it more clear whats a quote (and where from) and our notes

[clach04]

This is a good statement, it needs an explanation adding (steal the text from your PR, that text is perfect).

[clach04]

Recommend having a comment here, could simple say "see readme.testsuite.md for details"

[hab6]

@clach04 Thanks for your review. I added text from the PR to the new README and cleaned it up a bit, including your suggestions for making the quoted text distinct that is taken from the SQLAlchemy repository pages.

Please let me know of additional suggestions. Thanks.

[clach04]

Discussed with @hab6 - he'd like to hold off merge due to >50% tests being skipped. Want to review

[hab6]

Focusing solely on the tests in dialect compliance suite class ComponentReflectionTest:

Without the flag supports_schemas = False in the IngresDialect class, all reflection tests fail with this error (e.g. involving tables): [INGRES]CREATE TABLE: You may not create an object owned by 'test_schema'. Conversely, with the flag present in the IngresDialect class, the majority of the tests are skipped, yet many tests now fall into the PASS and FAIL categories.

Results of running ComponentReflectionTest class

IngresDialect class contains flag supports_schemas = False	PASSED	FAILED	ERROR	SKIPPED	TOTAL
No	0	0	732	0	732
Yes	131	104	0	497	732