CREATE TABLE the_table (was_char CHAR);

CREATE VIEW table_read_api AS SELECT was_char FROM the_table;

a client consumes data via:

select was_char from table_read_api;

after the change

alter table the_table modify was_char int;

alter table the_table rename column was_char to now_int;

CREATE VIEW table_read_api AS SELECT TO_CHAR(now_int) as was_char FROM the_table;

the client uses the same query

select was_char from table_read_api;

the type of the column has not changed

it is still a char

only "internal implementation" is changed