From: | Bo Lorentsen <bl(at)netgroup(dot)dk> |
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To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Index optimization ? |
Date: | 2005-01-19 06:40:18 |
Message-ID: | 41EE00D2.20508@netgroup.dk |
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Thread: | |
Lists: | pgsql-general |
Florian G. Pflug wrote:
> Because the _whole_ _point_ of an index is to find matching rows
> _without_ scanning the whole table. IF you have to look at every row
> anyway, then just might as well to an sequential scan.
I am sorry it took me this long to understand this, but I think I got it
now thanks to all Your (all in this thread) efforts to make me :-)
What confuses me was the difference between what controls a query and
what filters a row in a selected data set, I just could not see the
difference, but that have changed :-) I think the problem was I just
could not see the general principles from the special case where I
thought I had the use for this index lookup.
Thanks to anyone for there effort to make me understand, hope I will be
a faster learner next time :-)
/BL
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