Optimiser using incorrect statistics?

From: Jantah <jantah_at_big.hand.com>
Date: Sat, 02 Oct 1999 07:43:37 GMT
Message-ID: <37f5b3e4.787030@news.a2000.nl>

I have this query that used to run for some 5 seconds. After performing a new dataload on the database (we're still in a pre-live stage on this database), the query suddenly took a very long time to complete. When inspecting the query plan using the Topsession Monitor, I find that the 'expected rows' for two tables are way too low (78 and 1 insted of 30.000). When I do a SELECT * from either table, the query plan displays the correct amount of records. The table statistics look OK, and to be sure I did an analyze_schema, with the same result.

Am I misinterpreting the Topsession Monitor query plan, or is there something about these statistics that I need to know?

Using Oracle 7.3.3 on Solaris.
--
Jan
jantah_at_big.hand.com
(replace big.hand with bigfoot to email Jan) Received on Sat Oct 02 1999 - 02:43:37 CDT