Processors are used to process the items collected by a collector. They return an 'Implementor Class' string which is used to match against Datasets passed by a collection.
The DataListProcessor class is a basic processor which is used to delete a List of DataObjects from the Database.
Implementor Class: SilverStripe\ORM\DataList
The SQLExpressionProcessor class is more advanced processor which is used execute SQLDelete queries against the Database. It will convert any SQLExpression within a collection into an SQLDelete statement and process is.
Implementor Class: SilverStripe\ORM\Queries\SQLExpression
The RawSQLProcessor class is a basic processor which is used to execute raw SQL directly on the SilverStripe Application's Database. A Custom Model is provided so that Implementor Class matching can occur on the provided query.
Implementor Class: SilverStripe\GarbageCollector\Models\RawSQL