>
> Tom Lane wrote:
> >
> > Don Baccus <dhogaza@pacifier.com> writes:
> > > While I don't doubt your analysis is correct for the case you've
> > > uncovered, it doesn't explain why surrounding a bunch of selects
> > > with a begin/end block greatly descreases disk activity for tables
> > > that don't change.
> >
> > Hmm, I'm not sure why that should be, either. Anyone?
>
> >From a recent discussion I remember that every block that is read
> in is marked as dirty, regardless of weather it is modified or not.
>
> It is not a genuine bug (as it only slows thong down instead of
> getting wrong results), but still a misfeature.
>
> It is most likely an ancient quickfix for some execution path that
> failed to set the dirty mark when it should have.
Can't believe that this is true - uhhhhhh!
If it is, then it's surely a severe BUG!
Jan
--
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#========================================= wieck@debis.com (Jan Wieck) #