Optimizers

Hi,

        I just wanna' get something straight.

There are 2 types of query optimizers, rule-based and cost-based. Rule-based optimizers have certain rules that they use to optimize the 'where' clauses.
Cost-based uses statistics about tables (cardinality etc.) to optimize.

Oracle V6. has a rule-based, but no cost-based optimizer. Oracle V7 has both, but there has been complaints of that the cost-based one is slow.

I'd be grateful if anyone could tell me whether, I'm right, wrong, in the ballpark ...

Thanks,

        Rowan. Received on Mon Aug 16 1993 - 12:30:27 CEST