An extension that installs an immutable version of ash_raise_error.

This can be used to improve compatibility with Postgres sharding extensions like Citus, which requires functions used in CASE or COALESCE expressions to be immutable.

The new ash_raise_error_immutable functions add an additional row-dependent argument to ensure the planner doesn't constant-fold error expressions.

To install, add this module to your repo's installed_extensions list:

def installed_extensions do
  ["ash-functions", AshPostgres.Extensions.ImmutableRaiseError]
end

And run mix ash_postgres.generate_migrations to generate the migrations.

Once installed, you can control whether the immutable function is used by adding this to your repo:

def immutable_expr_error?, do: true