BEGIN;---- Add field foo to ingredient--ALTERTABLE"core_ingredient" ADD COLUMN"foo"text DEFAULT''NOT NULL;ALTERTABLE"core_ingredient" ALTER COLUMN"foo" DROP DEFAULT;COMMIT;

./0077_ingredient_foo.sql:2:1: warning: adding-not-nullable-field   2 | --   3 | -- Add field foo to ingredient   4 | --   5 | ALTER TABLE "core_ingredient" ADD COLUMN "foo" text DEFAULT '' NOT NULL;  note: Adding a NOT NULL field requires exclusive locks and table rewrites.  help: Make the field nullable../0077_ingredient_foo.sql:2:1: warning: adding-field-with-default   2 | --   3 | -- Add field foo to ingredient   4 | --   5 | ALTER TABLE "core_ingredient" ADD COLUMN "foo" text DEFAULT '' NOT NULL;  note: In Postgres versions <11 adding a field with a DEFAULT requires a table rewrite with an ACCESS EXCLUSIVE lock.  help: Add the field as nullable, then set a default, backfill, and remove nullabilty.