Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!harpo!seismo!hao!hplabs!sri-unix!SHARON@SU-SCORE.ARPA From: SHARON@SU-SCORE.ARPA@sri-unix.UUCP Newsgroups: net.ai Subject: Special Seminar--C. Beeri Message-ID: <3324@sri-arpa.UUCP> Date: Tue, 19-Jul-83 18:42:54 EDT Article-I.D.: sri-arpa.3324 Posted: Tue Jul 19 18:42:54 1983 Date-Received: Sat, 23-Jul-83 02:27:45 EDT Lines: 31 From: Sharon BergmanSPECIAL SEMINAR Thursday - July 21 - 2 P.M. Margaret Jacks Hall (Bldg. 460) - Room 352 CONCURRENCY CONTROL THEORY FOR NESTED TRANSACTIONS C. Beeri Nested transactions occur in many situations, including explicit nesting in application programs and implicit nesting in computing systems. E.g., database systems are usually implemented as multilevel systems where operations of a high level language are translated in several stages into programs using low level operations. This creates a nested transaction structure. The same applies to systems that support atomic data types, or concurrent access to search structures. Synchronization of concurrent transactions can be performed at one or more levels. The existing theory does not provide a framework for reasoning about concurrency in systems that support nesting. In the talk, a general nested transaction model will be described. The model can accomodate most of the nested transaction systems currently known. Tools for proving the serilizability of computations, hence the correctness of the algorithms generating them, wil be presented. In particular, it will be shown that the p r a c t i c a l theory of CPSR logs can be easily generalized so that previously known results (e.g., correctness of 2PL) can be used. Examples will be presented.