Re: Oracle Cost-Based Optimizer

From: Michael Taylor <mtaylor_at_postoffice.ptd.net>
Date: 1995/12/03
Message-ID: <49snas$ap8_at_ns2.ptd.net>#1/1


In article <30B4AC4D.5402_at_Bentley.nl>, Sybrand.Bakker_at_Bentley.nl says...
>Secondly, the cost-based optimizer reads from left to right instead of
>right to left. So
>from a,b,c
>will have table c driving in rule-based approach and table a driving
>in cost-based approach.

I assumed that the 'order' of tables in cost-based optimization would only affect 'driving' table as a 'tie-breaker' (i.e. after all paths were considered, weighted, etc.). Is this not the case? I would hope that cost-based would not resort to 'rules' in its path evaluations.

  • Mike Taylor
Received on Sun Dec 03 1995 - 00:00:00 CET

Original text of this message