supports_statement_cache support

[clach04]

Seeing https://docs.sqlalchemy.org/en/14/errors.html#error-cprf

ingres_sa_demo.py:18: SAWarning: Dialect ingres:pypyodbc will not make use of SQL compilation caching as it does not set the 'supports_statement_cache' attribute to ``True``.  This can have significant performance implications including some performance degradations in comparison to prior SQLAlchemy versions.  Dialect maintainers should seek to set this attribute to True after appropriate development and testing for SQLAlchemy 1.4 caching support.   Alternatively, this attribute may be set to False which will disable this warning. (Background on this error at: https://sqlalche.me/e/14/cprf)
  for row in connection.execute(sqlalchemy.text(query)):

[clach04]

Current code states no caching support, to avoid warning.

[hab6]

@clach04 Is there still work that needs to be done here? For what it's worth, I ran sa_orm_demo.py using sqlalchemy-ingres 0.0.4.dev1 with various versions of SQLAlchemy (2.0.25, 1.4.51, 1,4,42, 1.4,24) and the code executes successfully with no warnings.

[clach04]

@hab6 I think this depends on one's perspective, is this issue for:

1. warnings about caching
2. actually implementing caching support

I've been mentally treating this ticket as both; 1 is resolved but 2 is outstanding - but that may not be super clear from current write-up/description.

I vote for keeping this ticket open until we tackle number 2. Alternative would be to close and open/link a new ticket for actual caching support and update the title to explicitly mention warnings. What are your thoughts on this?

[hab6]

@clach04 Thanks for the clarification. I am in agreement to keep the ticket open with the remaining goal of implementing caching support, which is not something I have looked into at this point.