Robert Hansen did a talk at OSCON on a compressed annealing framework
called Djinni: <http://sixdemonbag.org/Djinni/>
It's a framework to use compressed annealing (a derivative of
simulated annealing) for finding approximate solutions to NP-complete
problems such as the TSP with time windows. Note that while Djinni is
implemented in C++, it already supports embedding via SWIG, and has a
C wrapper and is accessible from other languages. And it's
BSD-licensed...
This has the potential to be an alternative to the present use of GEQO
for query optimization for cases of large joins (e.g. - involving
large numbers of tables).
On the one hand, I'm somewhat suited to looking at this in that I have
the operations research background to know what they're talking about.
On the other hand, I'm not familiar with the optimizer, nor do I deal
with sorts of cases with so many joins that this would be worthwhile.
I've bounced a ToDo entry over to Bruce, and am making sure this is
documented here on pgsql.hackers so that a web search can readily find
it in the future...
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