optimizing pl*SQL

I'm running the following PL*SQL command

select
  c.course, t.description

       from course_table c, description_table t where c.course = t.course and
c.course = 'FRENCH100';

The course_table has 60000 records, the description_table has 2000. There is a unique index of "course" on the course_table. "COURSE" is also a primary key to the desription_table.

It takes a long time to run... so I used the EXPLAIN_PLAN to try and figure out what it's doing.

It's using a RANGE SCAN to get the course_table data,   BUT,
it uses a FULL scan to get the matching description on the description_table.

Either command by itself runs fast. It's only when doing the join that it takes a long time and does the full scan.

Does anyone know how to make it use the primary key on the description_table? (I've tried changing the order of the select and where clause, using various HINTS, etc.)

  Thanks.

-----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own Received on Fri Dec 04 1998 - 11:33:04 CST