Re: [GENERAL] Long update query ?

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> > This is caused by a semi-well known weakness in the optimizer.
> > The optimizer
> > rewrites the WHERE clause in conjunctive normal form (CNF):
> >
> >    (A and B) or (C and D) ==>  (A or C) and (A or D) and (B or C)
> > and (B or D)
> >
>
> Wouldn't disjunctive normal form be better, since it can be implemented as
> the simple union of a set of small queries?

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