Highly Concurrent Locking in Shared Memory Database Systems
Christian Jacobi and Cédric Lichtenau
University of Saarland -- Computer Science Department
PO Box 151150, 66041 Saarbruecken, Germany
{cj,cls}@cs.uni-sb.de,
http://www-wjp.cs.uni-sb.de/
Abstract. In parallel database systems, conflicts for accesses to
objects are solved through object locking. In order to acquire and
release locks, in the standard implementation of a lock manager small
sections of the code may be executed only by a single thread. On
massively parallel shared memory machines (SMM) the serialization of
these critical sections leads to serious performance degradation. We
eleminate the serialization by decomposing the complex database lock
needed for granular locking into basic lock primitives. By doing so,
we measured a speedup of a factor 200 on the SB-PRAM. Our method can
be ported to any architecture supporting the used lock primitives, as
most SMMs do.
LNCS 1685, p. 477 ff.
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