Another modelling requirement imposed by the Pull Mapper to model an operation called searchByLastwritten (you must use this exact spelling/case.
This operation should be a nsmulti. The value for no generated SQL should be no. The operation should take a struct called key. You should model your own struct as a parameter, but it must have an attribute called datetime, which must be a DateTime. Later you will specify the classname of this struct in the GSSEntity table, as described below.
You need to provide SQL for the operation. Here is a simple example for a simple entity called Customer:
Select Customer.customer_id, Customer.name, recordStatus from Customer WHERE Customer.lastwritten >= :datetime INTO :customer_id :name :recordStatus
You must ensure you are selecting all the columns used by the search service.
In addition to the table scan method, you must have a standard read method on all your searchable entities.