Support and considerations for federated three-part names
When working with federated three-part names, you need to be aware of supported function and environments, and when to use federated three-part names or nicknames.
Support for federated three-part names
- Db2® pureScale®
- Massively parallel processing (MPP)
- Serial mode
- INSERT, UPDATE, DELETE
- Positioned updates and deletes
- CREATE VIEW
- MERGE (the remote table cannot be a target table)
- UNION, INTERSECT
Support of three-part names in static SQL is limited to the Db2 and Oracle data sources. Static SQL statements that reference three-part names are always run with the VALIDATE RUN bind option. No dependency is recorded.
Considerations: When to use federated three-part names or nicknames
- Referencing remote objects for non-relational data sources
Federated three-part names are supported for relational data sources only.
- Defining informational constraints and creating indexes.
These functions are not supported for federated three-part names.
- Controlling authorizations and privileges at the object level.
You cannot control privileges for federated three-part names.
- Updating statistics.
Statistics are collected when you use federated three-part names to access the remote tables. However, because the metadata for remote objects is not in the federated database catalog, you cannot update statistics.
- For altering a column data type to a data type other than the default mapping, you need to use nicknames. As an alternative, you can create views over the federated three-part names or use casting functions in DML statements.