Re: What Indexes are being used?

From: James Lorenzen <jlorenzen_at_my-deja.com>
Date: Fri, 31 Mar 2000 14:33:22 GMT
Message-ID: <8c2cvi$ogu$1@nnrp1.deja.com>

In article <38E1DD47.93E_at_yahoo.com>,
connor_mcdonald_at_yahoo.com wrote:
> James Lorenzen wrote:
> >
> > Connor,
> > At a previous client, I had the same issue to deal with. The join
> > does tell you about indexes in the buffer and if the index never
> > appears in the buffer, it is not used. BUT, doesn’t the index
> > appear in the buffer if there are any changes in the fields
> > that are indexed? IE, if the table is changed (update, insert or
[Snipped]
> > James
> >
> > In article <38DF5C45.623B_at_yahoo.com>,
> > connor_mcdonald_at_yahoo.com wrote:
> > > Bruce Mackay wrote:
> > > >
> > > > Hi everyone,
> > > >
> > > > I've inherited support of a system with many indexes, probably
> > > > too many indexes!
> > [ Snipped ]
> > > > Bruce Mackay, BMM Pty Ltd
> > >
> > > Join X$BH (the buffer cache) to OBJ$
> > >
> > > This will tell you what objects are in the buffer cache. Using
> > > this you can periodically determine what indexes are in the
[Snipped]
> > > Connor McDonald
> > > http://www.oracledba.co.uk
> > --

>

> I use the FLAGS and CHANGES columns to check whether the buffer entry
> came from a straight read. If they are both 0 then the index was read,
> if not, then typically a write to that block has occurred.

>

> I can't categorically claim that this is correct - its just what I've
> observed and hence use.

>
> HTH
Thanks -- I did not get that far.

James
> --
> ===========================================
> Connor McDonald
> http://www.oracledba.co.uk

>

> We are born naked, wet and hungry...then things get worse
>
--
Life is complex; it has real and imaginary parts.

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Before you buy. Received on Fri Mar 31 2000 - 08:33:22 CST