Postgresql cannot alter type of a column used by a view or rule

check length type data

SELECT atttypmod FROM pg_attribute

WHERE attrelid = 'data_utama'::regclass

AND attname = 'nomor_sptm';

change type data

UPDATE pg_attribute SET atttypmod = 90+4, -- length type data 

atttypid='INT'::regtype -- type data

WHERE attrelid = 'data_utama'::regclass

AND attname = 'nomor_sptm';