CBO VS RULE

We are running a simple little query.

SELECT this_ID
FROM table
WHERE that_ID = 5

When executing the query with the database in choose mode it seems to want to do a full table scan, ignoring the index in the where clause. If we set it to RULE based mode obviously it works. What I am trying to convince my partner of is that it is not necessarily "wrong", it's just the way that the CBO wants to do it. We have analyzed the schema, the table and the indexes and this is the way it wants to go.

My question is, am I wrong? Is this a problem that I need to be concerned about?
Any help would be appreciated. Received on Tue Dec 19 2000 - 16:30:19 CST