The following scenarios illustrate how a reclaim vector algorithm works. Each scenario describes a user action, the cache structure environment at the time the user takes the action, the system response to the user action, and effects on the vector reclaims after the user action.

The user uses three storage classes, 1, 2, and 3. Before the user performs the first action, the user defines a reclaim algorithm for storage class 1 as follows:

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          IXLCACHE REQUEST=SET_RECLVCTR,RECLVCTR=VECTCLS1,STGCLASS=SCLS,REPEAT=REPT,
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 SCLS     DC  X'01' STORAGE CLASS
          DS  0H
 REPT     DC  H'2'  REPEAT FACTOR
 VECTCLS1 DC  H'2'  RECLAIMS TO BE MADE FROM STORAGE CLASS 1
          DC  H'0'  RECLAIMS TO BE MADE FROM STORAGE CLASS 2
          DC  H'1'  RECLAIMS TO BE MADE FROM STORAGE CLASS 3
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The request specifies that the system activate a reclaim vector to override the system default for data items in storage class 1. The reclaim vector indicates that the system can reclaim resources to satisfy the request from storage class 1 two times, cannot reclaim resources from storage class 2, and can reclaim resources from storage class 3 one time. The system can repeat this process two times before the reclaim vector for storage class 1 is deactivated, at which time the system begins to use the default reclaim algorithm.