With DB2 V8 it seems that we cannot override the sort parameters with a DFSPARM card.
We want to set the MAINSIZE and DYNALLOC parameters.
Now the job abend with code U16 and message : ICE046A 5 SORT CAPACITY EXCEEDED - The job is a REBUILD INDEX
DB2 V8 does NOT allow you to override those parameters using DFSPARM. They are supposed to figure out the optimal settings for those parameters based on what they're doing and don't want you to override that via DFSPARM.
I believe you can override the DYNALLOC parameters with DB2's SORTDEVT and/or SORTNUM parameters.
If you are having problems with the parameters DB2 sets and using SORTDEVT and/or SORTNUM doesn't help, then you should open a DB2 problem with IBM service so they can investigate the problem.