The concept unifies the persistence query objects which must extend Persistence\AbstractQuery
In the case of Persistence\Sql\Query the calls are forwarded to underlying DSQL object.

This abstracts the link to the actual query engine and unifies the use of Persistence\Query object in atk4/data irrelevant of persistence type.

The Model::load functionality has been moved to the Model object strictly leaving Persistence object to care only about raw data CRUD.

The Persistence CRUD methods have been moved to the generic Persistence class which relies on storage specific Query objects to perform the interaction with the data storage engine (Sql, Array (memory), Csv).

Array and Csv Query engines extend Persistence\IteratorQuery.

• Array_ persistence is using \ArrayIterator
• Csv persistence is using \SplFileObject which is also an iterator

If the concept is accepted it can be further worked on:

• introduce Model\QueryTrait to introduce direct access to query methods (insert, select, delete, etc) and use in the model object
• introduce optional Model\QueryAggregatesTrait to introduce direct access to aggregate methods (sum, avg, etc) and use in the model object
• optimize code

BC break:

• Model::action renamed to Model::toQuery
• Persistence::action renamed to Persistence::query