Allow a READONLY EXCLUDE clause
Listing the read-only columns for a UDO is fine when there is a known, small set of columns, but is really annoying when more of the columns are read-only than not. It would be nice if we could specify something like `READONLY EXCLUDE col2, col3`, where I specify only the columns that I know are going to be updated.
If a column was added to the source table, the developer has to remember to update all UDOs or not have ideal optimization. With a READONLY EXCLUDE clause, the code can run fully optimized regardless of whether surrounding columns are added or removed.