Pydantic itself uses a global settings dictionary for data models, so
follow this style for validation options.

This was needed in SQLAlchemy v1 but should not be needed in v2.

If there are 'mysql:datatype' annotations present in the column data,
check that they are not redundant.

The datatypes are checked to see if they compile to the same SQL
string in the target dialect.

Since the method to populate the ID map may be called multiple times if
the schema is updated after being built, it is safer to construct the
ID map in the post init hook rather than activate it using a validator.