At 07:11 AM 11/11/2003 +0000, you wrote:

>heLen, thanks for your advise. The select is faster now from 7 sec to
>2 sec. Should I remove history_idx2 or leave it as inactive.

Drop it.

> If set
>statistics on history_idx, will it cause the performance of insert
>drop ?

No, SET STATISTICS is a housekeeping function that you should do on all
indexes on large, dynamic tables from time to time, to keep the optimizer
up-to-date with their current state of distribution.

heLen