Re: pgstattuple extension for indexes

On Fri, Aug 18, 2006 at 09:15:59AM +0900, Satoshi Nagayasu wrote:
> ITAGAKI Takahiro wrote:
> > But the method has the above problem. So I suggest to use whether
> > the right link points to the next adjacent page or not.
> >
> >     if (opaque->btpo_next != P_NONE && opaque->btpo_next != blkno + 1)
> >         stat->fragments++;
> 
> Well, in that way, following two conditions,
>    [1] [x] [2] [y] [3]
> and
>    [3] [x] [2] [y] [1]
> will be calculated as same fragmentation ratio(100%), I can't agree
> with that, because both will generate different costs while index scan
> in the real world (I don't care about page splitting algorithm now).

What about just reporting the correlation of pages in the index, as well
as fragmentation?
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Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
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