17.10 - Changing the Value for Request Processing Option - Call-Level Interface Version 2

Teradata® Call-Level Interface Version 2 Reference for Workstation-Attached Systems

Product
Call-Level Interface Version 2
Release Number
17.10
Release Date
October 2021
Content Type
Programming Reference
Publication ID
B035-2418-061K
Language
English (United States)
If the value provided is not appropriate for the application, perform the following steps before calling DBCHCL for the Connect, Run Startup, or Initiate Request options:
  1. Change Options to 'Y'.
  2. Set the Request Processing Option value to:
    • E, if the database is to execute the request in the request string and send back the returned data,

    • P, if the database is to analyze the request in the request string, and if:

      Request is valid, send back a time estimate and format information about the data that it would return if the request were executed (the time estimate is the same as EXPLAIN returns)

      Request is invalid, send back an Error or Failure parcel (the same as if Request Processing Option is set to E).

      S, analyze each statement in the request.

      The statements may contain parameterized SQL. If the request is valid, the database returns a time estimate and format information about the data that would be returned if the request were executed.

      The time estimate is the same as EXPLAIN returns.

      The difference between the P and S mode is that P mode cannot contain a parameterized SQL request.

      B, analyze each statement in the request, then execute the request. The statements may contain parameterized SQL. If the request is valid, the database does return not only a time estimate and format information about the data that would be returned if the request were executed, but also the data resulting from the executed request. The time estimate is the same as EXPLAIN returns.

      B option is supported both in buffer and parcel modes.

      Segmented requests (TDSP) are not supported in S, B, and P modes. If these requests are submitted in either the S, B or P modes, the database returns a failure parcel with the error code set to 3749.

Request Processing Option is read by the call to DBCHCL for the Connect function and stored in the appropriate control blocks, but is not used during the connect.