SQL1582N The PAGESIZE of the table space "UNICA" does not match the PAGESIZE of the bufferpool "IBMDEFAULTBP" associated with the table space.

If you get the above error, it means you need to create a new bufferpool with a different page size as you require.

CREATE BUFFERPOOL UNICABPOOL  SIZE 3000 PAGESIZE 16K

Then use this bufferpool:

CREATE REGULAR TABLESPACE UNICA
    PAGESIZE 16K
    MANAGED BY DATABASE
    USING (FILE 'D:\DB2\NODE0000\UNICADB\UNICA.TBS' 80M) 
    BUFFERPOOL UNICABPOOL  AUTORESIZE YES