Tablespace-relative database pointers

摘要

A database containing datafiles is partitioned into a set of tablespaces. Every disk pointer pointing to a data item in a datafile refers to a tablespace-relative file number for the datafile. Data pointed to by a tablespace-relative disk pointer is retrieved by first checking the cache, and upon a cache miss, the tablespace-relative file number is translated into an absolute file number according to a latch-free look up technique.