Re: [HACKERS] 6.5 cvs: can't drop table

> Oleg Bartunov <oleg(at)sai(dot)msu(dot)su> writes:
> > today I did some tests with current 6.5 from cvs and multiple joins.
> > I did unpredictable server crashes, i.e. sometimes query works
> > sometimes crashes.
>
> I have a theory about why the results are random: the GEQO planner
> deliberately uses random numbers to generate plans, so you don't
> always get the same plan out of it. Whatever bug you are seeing
> occurs only for a particular plan path. (I haven't had any luck
> repeating your crash here, so the bug may be platform-specific.)
>
> It bothers me that the GEQO results are not reliably reproducible
> across platforms; that complicates debugging. I have been thinking
> about suggesting that we ought to change GEQO to use a fixed random
> seed value by default, with the variable random seed being available
> only as a *non default* option. Comments anyone?

I would leave the random alone. There may be some advantages to having
it random.

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