Preparing for migration

Preparing for migration includes gathering information about and backing up your data, so that you can reinstall the previous version of the server and restore your data if you have a migration problem. Preparing for migration is crucial for successful migration.

Review and complete all tasks that apply:

1. Reviewing changes in Informix product functionality.
2. Checking and configuring available space.
3. Configuring for recovery of restore point data in case an upgrade fails.
4. Renaming user-defined routines (UDRs) that have the following names: CHARINDEX() , LEFT(), RIGHT(), INSTR(), DEGREES(), RADIANS(), REVERSE(), SUBSTRING_INDEX(), LEN(), and SPACE().
   These names are reserved for built-in SQL string manipulation functions.
5. Adjusting settings:
   1. If you use UNICODE, ensure that the GL_USEGLU environment variable on the source server is set to the same value as the GL_USEGLU environment variable on the target server.
   2. If the source version of the database server contains the IFX_EXTEND_ROLE configuration parameter, which controls authorization to register DataBlade modules or external UDRs, disable the parameter by setting it to 0 (off).
6. Saving copies of the current configuration files.
7. Preparing 12.10 BSON columns with DATE fields for upgrade.
8. Closing all transactions and shutting down the source database server.
9. Initiating fast recovery to verify that no open transactions exist.
10. Verifying the integrity of the data.
11. Verifying that the database server is in quiescent mode.
12. Making a final backup of the source database server.
    Important: Complete the previous step in case you have to revert to the source database server.
13. Verifying that the source database server is offline.