Re: Creating multiple indexes
From: Vladimir Andreev <vandreev_at_gmail.com>
Date: Thu, 25 Nov 2010 15:13:07 +0100
Message-ID: <AANLkTi=AdCppEnMh=x=ZVMnE3TYDp24OrWNE0TqwPPPk_at_mail.gmail.com>
>
> On Wed, 2010-11-17 at 08:18 +0200, Laimutis.Nedzinskas_at_seb.lt wrote:
> Each create index needs to scan through every row in the table to form the
> index.
> i.e. 10 indexes = 10 full scans.
>
> Not necessarily. Oracle can scan an existing index to build a new one in
appropriate cases (new index columns a subset of existing index columns). You might want to order your CREATE INDEX statements accordingly. I've seen this happen as far back as 8i.
Date: Thu, 25 Nov 2010 15:13:07 +0100
Message-ID: <AANLkTi=AdCppEnMh=x=ZVMnE3TYDp24OrWNE0TqwPPPk_at_mail.gmail.com>
>
> On Wed, 2010-11-17 at 08:18 +0200, Laimutis.Nedzinskas_at_seb.lt wrote:
> Each create index needs to scan through every row in the table to form the
> index.
> i.e. 10 indexes = 10 full scans.
>
> Not necessarily. Oracle can scan an existing index to build a new one in
appropriate cases (new index columns a subset of existing index columns). You might want to order your CREATE INDEX statements accordingly. I've seen this happen as far back as 8i.
Cheers,
Flado
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Nov 25 2010 - 08:13:07 CST