Online document says: TUNE TABLE updates the SQL table definition (and therefore requires privileges to alter the table definition). Commonly, TUNE TABLE also updates the corresponding persistent class definition. This allows the gathered statistics to be used by the query optimizer without requiring a class compilation.
In terms of general through-put design and long term support, I'm considering what would be a "best approach" for needing to create multiple batch files in a few different layouts from the same data-sets.
By update