sns-seb

-- ##oracle
create TABLE TEST_SEB (
  COL_1 varchar(10),
  COL_2 varchar(10) NOT NULL
)
-- do not change nullity nor type
ALTER TABLE TEST_SEB MODIFY (
COL_1 varchar(10) NULL,
COL_2 varchar(10) NOT NULL
);

sns-seb

-- ##postgre
create TABLE TEST_SEB (
  COL_1 varchar(10),
  COL_2 varchar(10) NOT NULL
)

-- do not change nullity nor type
alter table TEST_SEB 
ALTER COLUMN COL_1 TYPE varchar(10),
ALTER COLUMN COL_1 DROP NOT NULL,