Re: [GENERAL] how to get accurate values in pg_statistic

Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > We do have:
> >     #geqo_random_seed = -1          # -1 = use variable seed
>
> > that lets you force a specific random seed for testing purposes.  I
> > wonder if that could be extended to control VACUUM radomization too.
> > Right now, it just controls GEQO and in fact gets reset on every
> > optimizer run.
>
> Actually, just the other day I was thinking we should take that out.
> Since there is only one random number generator in the C library,
> GEQO is messing with everyone else's state every time it decides to do
> an srandom().  And there is certainly no need to do an explicit srandom
> with a "random" seed every time through the optimizer, which is the
> code's default behavior at the moment.  That just decreases the
> randomness AFAICS, compared to letting the established sequence run.

Agreed.

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