There are times when CLI sends a request to the database for the next buffer-full of a response and it conflicts with a more recent request of the database. The rule is that a session may have the database active on its behalf for only one request at a time. This applies to the requests the application knows about as well as to the re-stocking requests done “behind the scenes.” If CLI is re-stocking response buffers, CLI returns “busy” from a call to DBCHCL for the Fetch function if Wait For Response is set to 'N'. This phenomenon is a possibility when a new request has been “refused.”
3691: Specified Buffer Size is too small in FastExport
only if the buffer remains too small after the expansion has taken place.