reading debug information from embedded SQL

Where I currently work we are not allowed to use the Navigator SQL optimizer
so I am wading through pages of joblog information. I will start
debug(strdbg) and step through the program and look at the joblog and try
and get optimization information. Is there a reference to read that will
help explain some of the information listed in the joblog. Here is a small
piece of one, but by no means the only lines.
Should I care about the join position?? 
The only thing I usually can get immediately is when it recommends an index
using certain key fields.
We are at v5r1. 

 Access path built for file OEPDIVRLGD.         
 Access path built for file *QUERY0035.         
 Access path built for file *QUERY0034.         
 Access path built for file *QUERY0036.         
 File OEPDIVRLG processed in join position 1.   
 File ACTCOMDIV processed in join position 2.   
 File OEPDIVRLGD processed in join position 3.  
 File OEPCUST processed in join position 4.     
 File *QUERY0035 processed in join position 5.  
 File *QUERY0034 processed in join position 6.  
 File *QUERY0036 processed in join position 7.  
 Temporary result file built for query.         
 **** Ending debug message for query .          
 ODP created.                                   

thanx
Larry Eckenrod