The SET ENVIRONMENT variable provides a mechanism for temporarily resetting certain features of the environment dynamically at runtime. The scope of these changes is local to the routine that executes SET ENVIRONMENT, rather than the entire session.
Exceptions to this local scope are the sysdbopen( ) and sysdbclose( ) SPL routines of Extended Parallel Server, which can set the initial environment for a session. For more information on these built-in routines, see Using sysbdopen( ) and sysdbclose( ) Stored Procedures (XPS).
Related statements: SET ALL_MUTABLES, SET PDQPRIORITY