Restrictions on optimized message transfers
IBM®
Informix® ESQL/C does
not chain the following SQL statements even when you enable optimized
message transfers:
- COMMIT WORK
- DESCRIBE
- EXECUTE
- FETCH
- FLUSH
- PREPARE
- PUT
- ROLLBACK WORK
- SELECT INTO (singleton SELECT)
When Informix ESQL/C reaches one of the preceding statements, it flushes the message out to the database server. Informix ESQL/C then continues message chaining for subsequent SQL statements. Only SQL statements that require network traffic cause Informix ESQL/C to flush the message queue.
SQL statements that do not require network traffic, such as the DECLARE statement, do not cause Informix ESQL/C to send the message queue to the database server.