From the perspective of the migration program, the migration process consists of the following steps:
This section provides a brief overview of each step. Detailed information about the steps and command syntax are provided later in this chapter.
The collection step, also known as the BUILDDB action, consists of gathering the existing Version 1 replication definitions into a DB2 database, the migration database, which will be used to store information during the migration process.
You can repeat the collection step, each time generating a new version of the registration and subscription details for analysis.
The migration database contains several global control tables, two of which store registration and subscription information from all specified Version 1 servers. Information contained in the Version 1 servers is added to the migration database during the collection phase. The tables in the database are created only at the beginning of the first collection step for each migration database, and contain information used in the later migration steps.
For more information about the migration database tables, see Tables in the Migration Database.
The analysis step, also known as the PREPARE action, consists of analyzing the contents of the global control tables in the migration database to detect potential migration exceptions and make necessary adjustments.
The migration analysis step does the following:
After reading the migration report, you can decide whether the automated migration choices are appropriate. If not, you can override the program's results by using standard SQL to update the data in the global control tables. Then you can rerun the analysis step to validate the current migration instructions.
The migration step consists of three actions: MIGRATE, FALLBACK, and CLEANUP. The MIGRATE action reads the replication definitions, original or modified at the analysis step, from Version 1 control tables and migration database, and migrates to Version 5 control table formats. This action can migrate one source server, one target server, or one of each (source and target) at a time. When this action is performed on a source server, views will be created for allowing the coexistence of the Version 5 capture program and the Version 1 Apply program.
Source server and target server are Version 5 terms that replace the DataPropagator Relational Version 1 terms of data server and copy server. The Version 5 terminology is used throughout this chapter.
You can back out of Version 5 migration and return to Version 1 using the FALLBACK action. If you choose this action, the program extracts the timely information such as timestamps and log sequence numbers from the current Version 5 control tables. It then updates Version 1 control tables with the extracted information base on the original or modified replication definitions in Version 1 control tables and migration database.
After successful migration, you can drop unused Version 1 tables and views using the CLEANUP action.