THE VIRTUES OF LOCKING BY SYMBOLIC NAMES OuriWolfson

We Propose, an algorithm for improVing the concurrency'of two philS~ locked transaction systems, ~hich use symbolic-name locki~g. The algorithm determines by preanalysis which entities .c~ri be unlocked Before all locks have been obtained, w.ithout c'ompromising ser'lalizability. This extendS tile work w~ published in [12], in three wa,ys. First, th~ transactions are .not restricted to, exclusive lobks, and may use shared locks as well. Seconq,. a methop·ls proposed to prevent the ~otential problem of cascading restarts, which results from unlocking of entities befon; conunitment: Third: the transactions"may be designed for a distributed database. Tel. ~(972)(4)293609; CSNET address: wolfson@tee:h-sel BITNET address: wolfson@TECHSEL . T ec hn io n C om pu te r Sc ie nc e D ep ar tm en t T eh ni ca l R ep or t C S0 41 6 19 86