FFU: Far-Future-Using Replacement Algorithms for Continuous Media Storage System

It is true that some conventional algorithms do not fit in Continuous Media (CM) environments because of their different properties. A typical example is the buffer replacement algorithmssuch as least recently used (LRU) and most recently used (MRU) strategies. These replacement policies are based on the referencing history for replacing buffered page with lower priority because it is not always possible to predict when a buffered page will be re-referred in a traditional DBMS. In contrast, since a CM storage system accesses CM segments sequentially, it can replace buffered segments which will not be re-referred in the near future. The idea of far-future-using (FFU) buffer replacement algorithm is to share the buffer for concurrent transactions and to keep segments in the order of re-referencing plan. In this paper, we analize FFU buffer replacement algorithm for CM playback in terms of buffer hit ratio and required buffer size in comparison with LRU and MRU.