From the manual:
"All indexes created by DB2 prior to Version 8 are type-1 indexes. All indexes created by Version 8 are Type 2 indexes, except when you create an index on a table that already has a type 1 index. In this case the new index will also be of type 1."
My interpretation is that if you drop
all the indexes on a table, and then recreate them, they will be type-2. However, if you have a primary key, you must drop it in order to drop the unique index.