P09-88-006VIRTUAL LOOKASIDE FACILITYABSTRACTA virtual lookaside facility is provided formaintaining named data objects in class-related dataspaces in virtual storage, readily retrievable by userprograms. A search order is associated with each user,specifying an ordered list of "major names" which are,in effect, sequentially searched for a specified "minorname", or data object, to obtain a virtual storage copyof that data object. As data objects are placed into avirtual cache, existence information, implicit in thenaming structure, is captured and saved. Thisinformation is relied on later in retrieving objectsfrom the cache. The data isolation provided bymaintaining class data and control blocks in individualdata spaces is exploited to prevent failures relatingto one class of objects from affecting the others, andto handle latent program users, following failures,effectively.An LRU-like trimming technique is used to removeless useful objects from the cache when cache space isfully utilized.
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