ABSTRACT

Oracle8i continues to enhance the buffer cache management improvements begun in Oracle 8.0 with the introduction of more sophisticated buffer replacement algorithms. Recall that in Oracle 8.0 the buffer cache was partitioned into multiple disjoint pools (DEFAULT, RECYCLE, and KEEP) into which specific blocks could be placed to accommodate different buffer aging requirements. Oracle8i contains enhancements to the buffer aging and replacement algorithms in the form of midpoint LRU insertion and touch count MRU promotion. These new features should result in better buffer cache performance out of the box, that is, without complex tuning analysis.