Hi everyone, first off, thanks for all the feedback! I'm glad to know that it works, it seemed like it should have to me.
1) Mark, Anton...Solved my problem. I had reversed the LIKE in my actual query from how I posted it! My result set always returned 0 records. Go figure that I posted the SQL correctly here yet had it messed up in my real query and couldn't spot the difference yesterday...
2) edafe...I'm using this to link chemical keywords to a description field in the main table. In an ideal database all entries in the main table would use a key number to uniquely identify them...but this is far from that ideal database!
3) sdude...While the performance will be worse using the LIKE join, the upside is that I can use other fields from my keyword table in the result set, worth it in my case. On a desktop edition SQL installation with 600k rows in the main table, going aginst 50 keywords was about a 10 sec query to return 2500 records. Certainly acceptable for my system.
4) Everyone else...Thanks for your posts! I'll be playing around with some of the other suggestions to see if I net any boost in performance.
A sidenote...GRRR--my responses keep disappearing when I post them...Is there a time limit between starting to type and posting successfully?