Re: Generic "Can I extend?" check

Richard Foote wrote:
>
> Hi Connor,
>
> You are a clever boy !!
>
> Quick question, where did you get these figures, are they documented
> somewhere or was it play and tell ?
>
> Cheers
>
> Richard
>
> Connor McDonald wrote:
> >
> > I've been asked to write a generic routine to determine if a segment can
> > extend. Easy enough except for auto-alloc lmt's where 'next_extent' is
> > null (ie indeterminate) in xxx_SEGMENTS.
> >
> > So here is my current compromise (in pseudo-code)
> >
> > where nvl(next_extent,
> > case
> > when initial_extent < 1m then
> > case when extents < 16 then next = 64k,
> > when extents < 80 then next = 1m,
> > when extents < 200 then next = 8m,
> > else next = 64m
> > when initial_extent >= 1m then
> > case when extents < 64 then next = 1m,
> > when extents < 184 then next = 8m,
> > else next = 64m )
> > > largest_free_space_chunk_in_tablespace
> >
> > The rough translation being:
> > - auto-alloc extents are 16x64k, then 64x1m, then 120x8m, then 64m, when
> > the initial_extent is less than 1m
> > - auto-alloc extents are 64x1m, then 120x8m, then 64m, when the
> > initial_extent is equal/more than 1m
> >
> > In the spirit of "open source", I'm throwing this out the community
> > asking for counter-examples which break the above formula.
> >
> > Thanks
> > Connor
> >
> > --
> > ==============================
> > Connor McDonald
> >
> > http://www.oracledba.co.uk
> >
> > "Some days you're the pigeon, some days you're the statue..."
>
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>
> Name: Richard.Foote.vcf
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Strictly play and tell...When you can buy 120G disk for 60 squid, it makes these tests somewhat easier :-)

C.

-- 
==============================
Connor McDonald

http://www.oracledba.co.uk

"Some days you're the pigeon, some days you're the statue..."