Open-requests is a count of requests that have not been ended. These requests do not necessarily still have spool files.
As long as the application keeps Open-requests less than or equal to 16, the number of spool files on the Teradata Database will be less than or equal to 16.
The Teradata Database allows no more than 16 spool files at one time per session.
For optimal performance, the application should operate so that Open-requests is no more than 16.
You should program your applications to close requests explicitly with a call to DBCHCL for the End Request function as soon as the response generated by the request is no longer needed.
DBCHCL updates Open-requests in the DBCAREA as soon as DBCHCL is called for a request-generating function.
Open-requests is available after the application regains control from DBCHCL, even for a connect operation.