Planning and performing a migration is a complex process requiring many activities to make sure that all the required software and information has been gathered.
All migrations are performed under the guidance of Teradata Customer Services staff, who work with you to develop a plan for system migration. The key to a successful migration is preparation.
- Download all necessary documentation.
- Install latest PUTTools package on system.
- Run the Pre-Migration Preparation script to identify and fix any problems. See Running the Pre-Migration Preparation Script.
- Prepare the destination system if different from the source system.
- Install the desired Advanced SQL Engine release and the latest Teradata Tools and Utilities on the destination system.
The time required to complete a migration will vary between systems. The most time consuming step is the actual transfer of all of the data from the source to the target system. The migration will take at least as long as it takes to perform a full system backup. Using DSA to restore data to a target system that has a different configuration than the source system requires significantly more time than was required to create the archive. This is because the restored data must be written one row at a time, while the archive was created using block-level I/O operations.
If you are changing the row format from packed to aligned, or from aligned to packed, it will require at least twice as long as a full system backup, because every data row must be rewritten, field-by-field, one row at a time.
After all of the data has been migrated to the target system the remaining steps and system validation will also vary, depending on the size of the system and the types of data objects.