Re: [Fwd: Re: System Statistics and the CBO]

Patty,

I must have misunderstood you. I thought you wanted to understand why the CBO was making a different index choice with system stats than without. As it turns out, the 10053 trace was not as helpful in this case as I'd hoped. If the problem was really just getting the query to use the right index, you could have used a hint or plan stability. Although changing the optimizer_index_cost_adj got you the desired result for this query, it could have an undesirable impact on other queries.

John Smiley

On 6/19/05, Patty.Charlebois_at_greenshield.ca <Patty.Charlebois_at_greenshield.ca> wrote:
>
> Wolfgang,
>
> You were correct in your speculation about optimizer_index_cost_adj=10
> causing the change in plan. I set optmizer_index_cost_adj=100 (the
> default) and explained my query with system statistics loaded and it is
> now using the correct index (x04claim_form) instead of the high card index
> (x01claim_form).
>
> Thank-you for all of your help!
>
> Patty
>
>

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