Is it safe to switch off cost based optimizing?

Our primary use of Oracle is to extract several million records at a time from a set of tables, where extraction order is critical.

Using the "order by" clause usually causes Oracle to do a full table sort, even if an index exists to generate the correct extraction order. So, in order to get correct extraction order, I over constrain the query with bogus "where" clauses until explain plan decides to use the index I want (which gives the correct extraction order).

We are currently using the cost based optimizer, but would like to switch to rule based. Will switching strategies alter the execution plan for extraction (and screw up the extraction order)?

We have NEVER run an analyze against any table.

We are on Oracle 7.0.15.

Any insight would be greatly appreciated.

Marty (output_at_netcom.com) Received on Sun Jan 29 1995 - 01:55:44 CET