The assessment process also includes analyzing the data used by your Pega application to determine which data must be migrated, and the approach for migration with respect to the overall size, rate of change, and acceptable cutover window.  The data migration plan must specify all source database schemas and tables that require migration to Pega Cloud, as well as how the data maps to the schemas and tables of the target database.  
If you have been using Pega software for a number of years, there may be data that you do not need to move.  Moving old data can be a complex process and add additional overhead to the migration window.  All applications evolve, and your data may contain information for old properties or data fields for parts of your application which are no longer being used.  It may be easier to purge or archive some old data tables rather than attempt to map these old properties to your newer functionality.

Reduce the overall size of the database

Instead of attempting to move a huge database that has been growing for years, consider expunging records to reduce the amount of data being migrated.  Expunging is only a viable option if you will never need those records again.

For more information, see Archiving and expunging case data 

Identify Tables Requiring Migration

There may be tables with old properties or tables which are entirely out-of-date that do not need to be migrated.  Review the database tables for your source database and categorize them as needing:

• No Migration
• Partial Migration
• Full Migration

Identify and clean up any tables that do not need to be migrated before the data migration. For any tables that need to be migrated, record these by name in your Migration Project Plan. Reference these when you submit the Cloud Change ticket for the data migration.

Archived Case Data

Identify any archived case data stored outside the database that needs to be retrieved or referenced through the Pega Platform after you migrate to Pega Cloud. Determine the size and source location or path of the archived data and include this in your Migration Project Plan.

Links and paths to archived artifacts need to be updated manually in the database after the archived case data is moved to the file repository provided with your Pega Cloud environment.

NOTE:  Archived data can be moved periodically after the Go Live.  As the client, it is your responsibility to move this data.

Storing Attachments

Pega does not recommend storing attachments directly in the database in your Pega Cloud Environment. Instead, archive attachments to an online repository after the production data migration is completed.

Attachments and file transfers are covered in the section Content Management and File Repositories.