I noticed the recent thread on cache busting. The last item mentioned
by Shel Kaplan about the use of unique URLs can be probably a good
motivation to use a different replacement policy than LRU. Lorenzo
Viciano and I have a report on this at

which suggests a different policy called LRV which uses -- among
other parameters -- the number of previous accesses to determine
how valuable is a document. The nice thing about LRV is that the
weight associated with the number of previous accesses to a document
is evaluated dynamically by a proxy: if the percentage of
documents with a single access increases, their weight decreases
and they are purged earlier.

Luigi Rizzo                     Dip. di Ingegneria dell'Informazione
email:       Universita' di Pisa
tel: +39-50-568533              via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522    

Received on Saturday, 30 November 1996 08:05:19 UTC