ARIESIIM: An efficient and high concurrency index management method using write-ahead logging

Abstract

This paper provides a comprehensive treatment of index management in transaction systems. We present a method, called ARIESIIM (A/gorlthm for Recovery and /so- /atIon Exploiting Semantics forlndex Management), for concurrency control and recovery of B+ -trees. ARI ES/lM guarantees serializability and uses write-ahead logging for recovery. K supports very high concurrency and good performance by (1) treating as the lock of a key the same lock as the one on the corresponding record data in a data page (e.g., at the record level), (2) not acquiring, in the interest of permitting very high concurrency, commit duration locks on index pages even during index structure modification operations (SMOs) like page splits and page deletions, and (3) allowing retrievals, inserts, and deletes to go on concurrently with SMOs. During restart recovery, any necessary redos of index changes are always performed in a pageoriented fashion (i.e., without traversing the index tree) and, during normal processing and restart recovery, whenever possible undos are performed in a page-oriented fashion. ARIES/lM permits different granularities of locking to be supported in a flexible manner. A subset of ARIES/lM has been implemented in the 0S/2 Extended Edition Database Manager.1 Since the locking ideas of ARIES/lM have general applicability, some of them have also been implemented in SQUDS and the VM Shared File System, even though those systems use the shadow-page technique for recovery.