You can use DMU garbage collection to perform the following functions:
Release disk space for other use
Reorganize Profiles for greater efficiency
Reorder structures by selected Profiles
Recreate all or selected Profiles from an Ispec structure
Select the Garbage Collection option on the DMU Home screen to display the Garbage Collection screen. Enter any non-space character in a property to select the option you require, subject to the following rules:
If you select ALL FILES, you might not select any other options except EDIT BUILDREORG.
You might only select one of ALL PROFILES or SELECTED PROFILES, and you might only select one of ALL COMPONENTS or SELECTED COMPONENTS.
If you select ALL FILES, ALL COMPONENTS, or SELECTED COMPONENTS, then by entering O (or o), you might also reorder some or all of the structures.
If you enter R in either the ALL FILES property or the ALL PROFILES property, then all Profiles are rebuilt (Refer to note under Selected Profiles).
Once all selection screens have been completed and transmitted as described in this section, the temporary DASDL file is created and scheduled for compilation, and you are returned to the DMU Home screen. At this point, your application can be enabled and started. (This applies to garbage collection only. For population changes, the DMU job must complete before the can be restarted.)
ALL FILES or ALL COMPONENTS
If you enter a non-space character in one of these properties, then garbage collection is applied to either all database files or all Ispec records, respectively.
If your non-space selection character is not an O or o, then no further selection screens are displayed.
Enter O or o to reorder some or all structures by selecting the Profile upon which the reordering takes place. Further screens are displayed, showing the Profile names for each structure in turn. These screens enable you to select a Profile for ordering the structure. Only Profiles that span the entire structure are shown.
If no Profiles are selected for a structure, then the structure order is undefined. If multiple Profiles are selected for ordering, then the first Profile you select is used.
ALL PROFILES or ALL EVENTS
If you enter a non-space character in one of these properties, then garbage collection is applied to either all Profiles or all Events, and no further selection screens are presented for these two properties.
If you enter Y in the Selected Profiles property, a Profile Options screen is displayed for you to select the Profile to be recreated from the Ispec structure. This will have a similar effect to entering O in the All Files or All Components property, in that the order of duplicates in the Profile might change.
Note: Rebuilding from the Ispec structure might cause an impact on your performance. Refer to the DMS II Utilities Guide for more information.
SELECTED COMPONENTS
If you enter a non-space character in this property, a screen showing Ispec names for your selection is displayed. Enter a non-space character in the properties for those Ispecs you want to include in your garbage collection.
Enter O or o to reorder your selected Ispecs by selecting the Profile upon which the reordering take places. Further screens are then displayed, showing the Profile names for each structure in turn. These screens enable you to select a Profile for ordering the structure. Only Profiles that span the entire structure are shown.
If no Profiles are selected for a structure, then the structure order is undefined. If multiple Profiles are selected for ordering, then the first Profile you select is used.
If you have also chosen SELECTED PROFILES, the appropriate screen is displayed after you have selected your Ispecs. Refer to Selected Profiles for more information.
SELECTED PROFILES
If you choose this option, a screen is displayed showing Profile names for your selection. Enter a non-space character in the properties for those Profiles you want to include in your garbage collection run.
Enter R to rebuild the Profile from the Ispec (instead of rebuilding from the default value). This is useful for recreating Profile structures that have been lost or corrupted but it might have some performance implications during the reorganization.
If you have also chosen SELECTED COMPONENTS, the Ispec Selection screen is displayed before the Profile Selection screen. Refer to Selected Profiles for more information.
EDIT BUILDREORG
Enter a non-space character in this property to access the BUILDREORG EDIT screen. This allows you to control the order of the reorganization processes, to improve performance.
The relevant Ispec screens are displayed depending on the parameters you select.
The BUILDREORG EDIT screen is displayed with the current Generate or Central Data Set statements when each statement is created. Only the first 15 lines of the statement are displayed per edit screen, and up to three pages of any one statement are displayed.
Edit each BUILDREORG statement to add the syntax required. The BUILDREORG syntax is described in the DMSII Utilities manual. No syntax checking is performed on your edited statements.
Enter any of the following into the properties on the BUILDREORG EDIT screen:
1, 2, or 3 in the Next page number property to display that page within the statement.
D in the Done/Last property to write the statement to the parameter file and skip to the next statement.
L in the Done/Last property to write the statement to the parameter file and skip to the last statement (the Central Data Set statement).
If you complete both the Done/Last property and the Next page number property, the Next page number property is ignored.
To terminate an edit session, enter L in the Done/Last property to go to the Central Data Set statement then enter D in the Done/Last property. The edited parameter file is submitted to the BUILDREORG utility. You need to check the system messages to see if there are any syntax errors in the parameter file.