Re: Use "average field correlation per hard disk

At 04:08 PM 10/03/2004, Tom Lane wrote:
>None at the moment, but I'm open to suggestions.  It seems like we might
>need different stats for equality probes than range probes.

What about my suggestion from August 2000:
    "There might be a way to side-step the issue here. I assume that    the index nodes contain a pointer to a record
ina file, which    has some kind of file position. By comparing the file positions    on one leaf node, and then
averagingthe node cluster values,    you might be able to get a pretty good idea of the *real* clustering."
 

I don't use the CLUSTER command, but I have clustered data and would like 
to be able to take advantage of the fact if possible. *If* the record 
pointers can be used to indicate closeness, then the same approach of 
randomly sampling index nodes would seem to work. Then again, maybe I don't 
know enough about the storage techniques...




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