MANAGEMENT OF USER-DEFINED ROUTINE LIBRARIES IN DATABASE ENVIRONMENTS

摘要

Library management for libraries of user-defined routines in a database system. Libraries are stored in a long-term storage device and loaded into working memory in t he database system when routines in the libraries are to be executed. An unload thread is defin ed to carry out the process of unloading libraries from the working memory when such libraries are inactive. The unload thread becomes active on a defined timing interval. The unload thread accesses a ha sh table and a most recently used list to determine which of the loaded libraries is inactive an d which of the libraries ought to be unloaded. The hash table maintains information as to which libraries have been accessed in the most recent past defined timing interval. The size of the most recent ly used list can be defined such that all libraries associated with the list are retained in working memory.