TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Lessner, Tim A1 - Laux, Fritz A1 - Connolly, Thomas T1 - O|R|P|E - a data semantics driven concurrency control mechanism with run-time adaptation JF - International journal on advances in software N2 - This paper presents a concurrency control mechanism that does not follow a "one concurrency control mechanism fits all needs" strategy. With the presented mechanism a transaction runs under several concurrency control mechanisms and the appropriate one is chosen based on the accessed data. For this purpose, the data is divided into four classes based on its access type and usage (semantics). Class O (the optimistic class) implements a first-committer-wins strategy, class R (the reconciliation class) implements a first-n-committers-win strategy, class P (the pessimistic class) implements a first-reader-wins strategy, and class E (the escrow class) implements a first-n-readers-win strategy. Accordingly, the model is called OjRjPjE. The selected concurrency control mechanism may be automatically adapted at run-time according to the current load or a known usage profile. This run-time adaptation allows OjRjPjE to balance the commit rate and the response time even under changing conditions. OjRjPjE outperforms the Snapshot Isolation concurrency control in terms of response time by a factor of approximately 4.5 under heavy transactional load (4000 concurrent transactions). As consequence, the degree of concurrency is 3.2 times higher. KW - transaction processing KW - multimodel concurrency control KW - optimistic concurrency control KW - snapshot isolation KW - performance analysis KW - run-time adaptation Y1 - 2016 U6 - https://nbn-resolving.org/urn:nbn:de:bsz:rt2-opus4-8397 UN - https://nbn-resolving.org/urn:nbn:de:bsz:rt2-opus4-8397 UR - http://www.iariajournals.org/software/tocv9n12.html SN - 1942-2628 SS - 1942-2628 VL - 9 IS - 1/2 SP - 62 EP - 79 S1 - 18 PB - IARIA ER -