Deciding whether to use QMF or GDDM services for printing

Whether you print using GDDM services or QMF services depends on what type of objects you need to print and what types of printers and other resources are available to you. Use this section to help you decide which method suits your needs.

• If you need to print charts, forms, or prompted queries, use GDDM.

  QMF uses GDDM services to display these objects; GDDM must be used to print these objects as well. If you do not use GDDM services, you can print only reports, tables, QBE and SQL queries, procedures, and the QMF profile.

• If your site is set up to route output to named printers, use GDDM services for printing.

  GDDM allows you to link a name with a physical device. If you do not use GDDM and use exclusively QMF services, you need to print objects by specifying the type and name of the storage queue through which those objects are routed to the printer.

Both QMF and GDDM handle printer input asynchronously, which means that QMF can return messages indicating that the object is printed before it is actually printed.