We have a requirement to move the work data from IBM DB2 to MS SQL DB and use the blob data and move the information to another data table. This data table will be used for search purposes for old case information. I have moved the data to MS SQL DB. When I create a work class and map the table. This is considered as external data table and px,py,pz not recognized and able to use only the exposed columns in the work table.

Class X is mapped to foreign data table Y in database PegaDATA, but it contains a px, py, or pz property

Need suggestions/solutions to move forward.I would like to know how pega manages the data migration to pega saas with these scenarios and able to consider the table as internal table?

Note: Exposing the data before migration is an option which I am not looking for.