Appendix B: Performance Considerations
This appendix highlights the factors that can effect the performance of ALC menus.
The objects in library ALC are shipped in compressed format. The first time you use ALC, most of the ALC objects are automatically decompressed. Due to this automatic object decompression, you may notice a slight delay the first time you use ALC.
The first time an ALC menu is displayed for a job, menu programs and work spaces are initialized for that job. Due to this initialization, you may notice that it takes slightly longer to display the first menu for a job as compared with any subsequent menus. This initialization is performed once per job, unless you use the following command to explicitly deactivate the menu driver:
RCLACTGRP ALC
Security Filtering of Menu Options
When a user displays an ALC menu, they only see the options to which they are authorized. ALC builds the display for large menus one page at a time. In the process of building a page of the display, ALC checks the user's authority to each menu option before adding the option to the menu. If the user is not authorized to a large percentage of the menu options for a large menu, the user may notice a delay in displaying the menu as ALC checks the authority for many menu options in an effort to build a single page of the display.
Authority checking is done for each page of a multi-page menu as the page is first displayed. Using the Roll/Page keys to move back and forth through pages of the menu that have already been displayed does not cause the authority for the menu options on those pages to be checked again. Pressing F5 to refresh the menu display does cause menu option authorities to be checked again.
Using the Position to field on a multi-page menu to switch directly to a particular page of the menu will take longer if:
· The menu has many options.
· The requested position is at the end of the menu and many pages of the menu between the current page and the requested page have not yet been built. Individual pages of the menu are built when the user pages forward to a particular page with the Roll/Page keys. Groups of pages may be built when the user uses Position to to skip forward. In that case, all pages that have not yet been built between the current page and the requested page are built in order to satisfy the Position to request.
If a menu is set to ignore *ALLOBJ authority when determining which options to allow the user to access, it will take slightly longer to build each page of the menu for those users that do have *ALLOBJ authority. Performance is not effected for users that do not have *ALLOBJ authority.
See Creating Menus for more information about ignoring *ALLOBJ authority.