Re: using indexes

From: Kevin Brand <kevin.brandx_at_tel.gte.com>
Date: Thu, 7 Dec 2000 12:47:43 -0600
Message-ID: <90olu8$lp6$1@news.gte.com>

You could try to do what the Optimizer does when a HISTOGRAM is available via your application code. However, that can be fairly complicated.

Try defining a HISTOGRAM for the indexed column(s) in question. This will allow the optimizer to decide whether an index-scan will be more efficient than a table-scan based on samples of the actual column data.

-Kevin

<letokai_at_my-deja.com> wrote in message news:90ofte$llf$1_at_nnrp1.deja.com...
> I've read that the use of indexes was efficient only if the value
> selected is not frequent in the table and that it costs very much if
> it's frequent
>
> is there a way to know if this value is frequent or not?
> I mean if you have a generic program that does not know what's in the
> table it's reading? Is there a way for that program to know if using
> the index will be good or not?
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Thu Dec 07 2000 - 12:47:43 CST