- Please explain and expand what do you mean by core persistence services.
But from what I've understood (and assuming you're not using any ORM) the general services would be,
1. Find rows by primary key.
2. Save a row.
3. Save a bunch of rows.
4. Cascade save rows (typically parent-child entities).
5. Form dynamic sql based on search conditions (search condition can be generic or specific).
6. Update/delete a row based on primary key.
7. Services which would open/close transactions (point-point or distributed).
8. Services which would do logging of DB operations (If you plan to have in your application)
These are some of the things which comes to the top of my mind.
If you are not laughing at yourself, then you just didn't get the joke.