Strange Explain_plan

Hi,

I executed a new procedure today that seamed to take a long time to run.

I ran explain plan and the result said it was doing a full table scan on a certain table.

The select has 3 out of 4 parts of the table's unique index defined.

I changed the select (within explain plan) by adding the 4th part of the unique key and ran explain plan again. This resulted in the table being accessed by it's unique key (like it should).

I removed the 4th part (the one I just added to the select) and ran explain plan again. This time it said that the table was using a rangecan via the unique key (like it should).

I executed the same procedure again and it ran alot faster than before.

So, why would the table be accessed differently now than before?

Oracle 7.3.4.3.0, AIX

Thanks alot,
-John Received on Wed Mar 22 2000 - 12:33:24 CST