Re: GEQO status?

Ed Loehr writes:

> What is the status of the genetic algorithm query optimizer? Is this
> supposed to work well on many-table joins, or has it fallen out of favor
> or in disrepair? [I'm needing to optimize some large, many-table-join
> queries and wondering time spent configuring/understanding geqo would be
> fruitful...]

I've seen a number of bug reports that would indicate to me the GEQO works
less than perfectly. I vividly recall how, while working on my own code,
mere additions of dummy clauses like '... AND 5=5' altered query results
in seemingly random ways. That was admittedly quite a while ago, but the
GEQO code hasn't changed since. I'd advise you to be *very* careful.

--
Peter Eisentraut peter_e(at)gmx(dot)net http://yi.org/peter-e/