At 09:04 PM 10/3/2002 +0000, danielberstein wrote:

>I have an indexed column where a simple "SELECT MAX(<column>) FROM
><table>" generates a full table scan. I guess it has to do with the
>index compresion stuff I read somewhere. This particular table has
>over 1.5 million records (the database has plenty of super populated
>tables).

It has less to do with the compression than on the fact that
index nodes on any particular level have reliable links to their
neighbor to the right, and unreliable links to the neighbor to
the left. A descending index will solve the problem, though often
a slightly different design will avoid the need for SELECT MAX
entirely.

>BTW, how does index compression affect negatively on geographic
>coordinates (lat/lon, UTM)? If there is a problem, is there any
>workaround (perhaps storing hours, minutes, seconds instead of
>decimal notation?).

There should be no problem with decimal notation of geographic
coordinates.



Regards,

Ann
www.ibphoenix.com
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