In this work, we devise and evaluate control strategies for combining two potentially powerful buffer management techniques in object bases: (1) buffer pool segmentation with segment-specific replacement criteria and (2) dual buffering consisting of copying objects from pages into object buffers. We distinguish two dimensions for exerting control on the buffer pool: (1) the _copying_ time determines when objects are copied from their memory-resident home page and (2) the _relocation_ time determines the occasion on which a (copied) object is transferred back into its home page. Along both dimensions, we distinguish an _eager_ and a _lazy_ strategy. Our extensive experimental results indicate that a lazy object copying combined with an eager relocation strategy is almost always superior and significantly outperforms page-based buffering in most applications.
Ulrike Peiker, Martin Griebl