The following alter table with default set to very large text used to work in Postgres 10 but fails in Postgres 12 with ERROR: row is too big: size 12960, maximum size 8160
create table test (id int); alter table test1 add column license text DEFAULT '<insert default text with size more than 8160 >'
The following two variants works in Postgres 12 without any error:
create table test (id int);
alter table test1 add column license text alter table test1 alter column license SET DEFAULT '<insert default text with size more than 8160 >'
create table test (id int, license text DEFAULT '<insert default text with size more than 8160 >' );
