We are currently experiencing cases of mixed-up (and therefore incorrect) metadata for some newly indexed journal issues. We are aware of the problem and we are working on a fix. Thanks for understanding and we apologize for the inconvenience.
Query optimization in modern database management systems faces in
many cases large access plan spaces. This papers addresses the case
of recursive queries where the optimization space is very large and
requires special treatment. I particularly liked this paper because
it introduced for the first time advanced optimization techniques,
in this case simulated annealing, to the problem of query
optimization. Simulated annealing is a probabilistic hill climbing
algorithm. The authors study in details the basic factors
influencing the performance of the algorithm and provide in a neat
and "educational" manner implementation issues. In my opinion this
is a model paper for people writing query optimization algorithm
papers, where sometime details are not presented and readers are
left with lots of questions.