db_migrate command

The db_migrate command copies Netezza® Platform Software databases or specific tables from a source Netezza system to a target Db2® environment.

The db_migrate command is part of the Db2 support tools, and is based on a similar Netezza utility called the nz_migrate command. For information about obtaining the support tools, see Db2 support tools overview.

Migration scenarios

You can use db_migrate to migrate data from Netezza (NPS) versions 7.0.3 or later, to the following Db2 products:
  • Db2 Warehouse
  • Db2 Warehouse on Cloud
  • Integrated Analytics System
The target database must have STRING_UNITS set to default value SYSTEM.

You can also use db_migrate frombackup command to migrate data from Netezza backup. For more information, see Migrating data from a Netezza backup.

The following migration scenarios are not supported with db_migrate command:
  • NPS > NPS
  • Db2 Warehouse > NPS
  • Db2 Warehouse > Db2 Warehouse
  • NPS lowercase system > Db2 Warehouse
  • NPS versions prior to 7.0.3 > Db2 Warehouse

Important considerations

When you use the db_migrate command to copy data, the data transfers automatically between the source Netezza and target Db2 system. The database environments are very similar, but there are some important differences.
  • A Db2 warehouse has one database, BLUDB. When you move Netezza databases to Db2 warehouses, the databases are created as schemas within the BLUDB database. You can specify the target schema name in the db_migrate command.
  • Most Netezza data types have equivalent types in a Db2 warehouse. Some types, such as TIME WITH TIMEZONE (TIMETZ), do not currently have corresponding types in a Db2 warehouse. The db_migrate command uses the IBM® Database Conversion Workbench (DCW) Lite utility to make automatic data conversions, but some manual changes might be required to fine-tune the data types or user queries after the data is loaded into a Db2 warehouse. You should use the DCW Lite tool to run a conversion assessment to identify possible migration concerns before you use db_migrate to copy large amounts of data.
  • The Db2 TIME data type does not support the microseconds portion of the Netezza TIME data type (for example, 999999 in the value 23:59:59.999999). During migration from Netezza to Db2, the microseconds are truncated. The difference is not reported when running checksum after migration, even if full checksum is set.
  • Some Netezza features might not yet be available in a Db2 warehouse. The db_migrate command and DCW engine display messages about the progress of the data transfer and possible syntax or migration considerations.

You should test the db_migrate command with some small sample databases and tables. Run the tests to confirm that you have the connection details for each system, and that the network connection between your systems supports the data transfer.