Restrictions on altering server definitions
You need to be aware of several restrictions when you alter server definitions.
The following restrictions apply to altering server definitions:
- You cannot specify a wrapper in the ALTER SERVER statement that is not registered with the federated server.
- The federated server cannot process an ALTER SERVER statement
within a given unit of work (UOW) under either of the following conditions:
- The statement references a single data source, and the UOW already
includes one of the following statements:
- A SELECT statement that references a nickname for a table or view within the data source
- An open cursor on a nickname for a table or view within the data source
- An insert, delete or update issued against a nickname for a table or view within the data source
- The statement references a category of data sources (for example,
all data sources of a specific type and version), and the UOW already
includes one of the following statements:
- A SELECT statement that references a nickname for a table or view within one of the data sources
- An open cursor on a nickname for a table or view within one of the data sources
- An insert, delete or update issued against a nickname for a table or view within one of the data sources
- The statement references a single data source, and the UOW already
includes one of the following statements:
- The federated server does not verify whether the server version that you specify matches the remote server version. Specifying an incorrect server version can result in SQL errors when you access nicknames that belong to the database server definition. These SQL errors are most likely to occur when you specify a server version that is later than the actual version of the remote server. In that case, when you access nicknames that belong to the server definition, the federated server might send SQL to the remote server that the remote server does not recognize. On the ALTER SERVER statement, this situation applies only to the form of the statement that alters the server version (server-name VERSION server-version).
- You must specify the full server option name. For example, you cannot specify the abbreviation DB2_TWO_PHASE. Instead, you need to specify the full server option name DB2_TWO_PHASE_COMMIT.