Join 2 files with 1 key from each file.

I have 2 files I want joined and indexed on 1 key from each of the 2
files.

The 2 files are named s1 and s3, both have the common field of Order#
(on) in them

s1 JOIN s3 ON s1on = s3on .

I want the joined file indexed by s1name, then s3itno

ORDER BY s1name, s3itno .


I'm using embedded sql in rpg and everything works fine except the
response
time on one of our production machines gets to be 5+ minutes.!

---->
I want to have a prebuilt, index or logical so that when this program is
used, the response time will fall into the acceptable range.

I've built most every combination of logical file (using dds) to this
end
but the response time is still horrid.

The s1 file has 2.25 million records and the s3 file has about 2.8
million.

Can anyone give me some guidance on this please?  I've tried everything
I can think of for the last day or 2 and response time is still crappy.


Thanks for any help at all,

John B.