Re: cost based optimizer vs rule based optimizer

Vic Arcabos wrote:

> For large tables, you can save time by analyzing just a percentage of the table:
>
> example: analyze table XXXXX estimate statistics sample 10 percent;
>
> This should provide good statistics for CBO without taking the time to analyze the
> whole table.
>

absolutely !

but also...
We have tables of 5Gb + and so even 10% is too much. We tend to use "sample 5000 rows" or such like and get reasonably good stats.

Simon. Received on Thu Jun 25 1998 - 00:00:00 CDT