Re: Index design question

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Mon, 29 Nov 1999 09:10:01 -0000
Message-ID: <943866709.21063.0.nnrp-04.9e984b29@news.demon.co.uk>

It is theoretically possible.
Bitmap indices can work with range scans.

The explain plain on the two date ranges is likely to show something like:

bitmap OR

        bitmap merge
            bitmap index open_idx (range scan)
        bitmap merge
            bitmap index close_idx (range scan)

If the path just doesn't drop out automatically from the CBO, you can probably force it by using the index_combine hint.

Jonathan Lewis
Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk

michael_bialik_at_my-deja.com wrote in message <81s47r$81c$1_at_nnrp1.deja.com>...
>Thank you for your help.
>
> I implemented it and it works just fine ( with B-tree indexes ).
> Is it possible to use bitmap indexes here ?
> As far as I know they are useless for supporting range-scan queries.
>
Received on Mon Nov 29 1999 - 03:10:01 CST