How reliable are the cost figures from Plan Table

From: PMG <pete_g_at_2xtreme.net>
Date: Fri, 19 Mar 1999 05:06:51 GMT
Message-ID: <36F1DBBC.FE5F1939@2xtreme.net>

I am running on Oracle 7.3, and the optimizer is RBO. Setting autotrace on, I get output that shows

Execution Plan

0 SELECT STATEMENT Optimizer=HINT: FIRST_ROWS (Cost=1950 Card=32000 Bytes=26208000)

My question is this: since the tables in the query have never been analyzed, and am running in an RBO environment, what is the meaning of the Cost, Cardinality, and Bytes values shown above. Can I rely on them for optimization purposes/

TIA Pete Received on Thu Mar 18 1999 - 23:06:51 CST