boolean column for oracle database tables

CREATE TABLE booleans
( 
isBoolean char(1) DEFAULT 1 NOT NULL CHECK ( isBoolean (1,0) )
);
 
comment ON COLUMN booleans.isBoolean IS 'boolean: 1 for True, 0 for False';
 
CREATE bitmap INDEX isBoolean_index_name ON booleans(isBoolean);
 
 
 
ALTER TABLE
  table_name
ADD
  (
  is_boolean integer DEFAULT 1 NOT NULL CHECK ( is_boolean IN (1,0) )
  );
 
comment ON COLUMN table_name.is_boolean IS 'boolean: 1 for True, 0 for False';
 
CREATE bitmap INDEX is_boolean_index_name ON table_name(is_boolean); -- Faster sorting and searching for low-cardinality data
 
 
SET serveroutput ON
begin
  dbms_output.enable;
  IF package.boolean_function then
    dbms_output.put_line('True');
  else
    dbms_output.put_line('False');
  end IF;
end;
/