Re: Another index question

From: Sybrand Bakker <gooiditweg_at_sybrandb.demon.nl>
Date: Tue, 01 Jul 2003 22:46:35 +0200
Message-ID: <rlr3gvkm7kon8k2hio7p4h0a1k3me7ml5i@4ax.com>

On Tue, 1 Jul 2003 12:22:18 -0700, "dsb" <dana_at_iqms.com> wrote:

>For tables that have indexes at one column per index (for the columns that
>have indexes), is there any benefit (apart from possibly storing data more
>efficiently) to combine the columns into one index? Could it save an I/O or
>two, for example?
>
>Background - we just stopped supporting Oracle 7 so we haven't (yet)
>implmenented bitmap indexes, IOT's, etc.
>
>Thanks,
>dsb
>

Oracle is capable of merging indexes on the fly. So the answer to generic questions like this one is, as usual: it depends.
The problem with your approach is that you may likely setup an incorrect column as 'leading', so your index isnt' being used anyway.

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Tue Jul 01 2003 - 15:46:35 CDT