If I do ... select 1::NUMERIC + 1::BIGINT; I get ... [42725] ERROR: operator is not unique: numeric + bigint Hint: Could not choose a best candidate operator. You might need to add explicit type casts. This error means I have more than one way to calculate that formula ? Did I create that operator erroneously ? If so, how can I see what I did and how to fix it ? I tried but didn´t find any answer. select * from pg_operator join LATERAL ( select typname::text from pg_type where pg_type.oid = oprleft ) l(oprleft_name) on TRUE join LATERAL ( select typname::text from pg_type where pg_type.oid = oprright ) r(oprright_name) on TRUE join LATERAL ( select nspname from pg_namespace where pg_namespace.oid = oprnamespace ) n(namespace) on TRUE -- Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html