Re: massive delete

Hello George,
do you wirk with cost-based optimizer ?
Try to analyze your table just before delete the rows or
try to delete statistics (with analyze table xxxx delete statistics;) both tries with optimizer_mode=choose

Tell me the result please, I am interested by it

Regards. Olivier

George Meltser wrote:

> I hope somebody can help me.
> At night we have to replace about 20% of our data.
> First we delete the rows then insert the new ones.
> Delete may take any time from 2 to 4 hours.
> I did SQL_TRACE many times and was really surprised that amount of time it
> takes to delete the same number of rows from the same table changes from day
> to day dramatically, let's say from 3 min to 28 min or from 54 min to 22.
> The load on the server is the same at this time.
> What may cause those delays?
> None of these tables have chained rows, all are stored in 1 extent, i have
> not changed indexes on them for about 6 months.
> Is it Rollback segment shrinking?
> Thanx in advance,
> Regards,
> George
Received on Sun Apr 05 1998 - 00:00:00 CST