Re: How is possible that avg_data_blocks_per_key = 0 even with fresh statistics ?

But you're right, I forgot important details: the two tables aren't empty, they contain 9 and 13 rows respectively. Statistics are collected every morning and table contents didn't change since then.
The index involved is, by the way, the primary key.

On the slow site I tried collecting system statistics for a short time (20 minutes) and I observe now a gain in performance on the slow query
(25000 consistent gets now instead of more than 150k). The plan is so big that is difficult to see the difference (but who cares if the query run at speed ?)
No system stats are in place on the site #2

Still I don't understand how index statistics on site #2 can be empty ......????

> Sorry just not enough caffeine in me yet. Maybe the table at one site
> was truncated/empty when the stats were gathered?
>
> That way the stats "can be current" yet still useless and not helpful
> to the optimizer after data has been placed into the table.
Received on Thu Dec 06 2007 - 08:13:16 CST