Hello, A colleague of mine was surprised to discover the following statements raised an error:
postgres=# CREATE TYPE abc_enum AS ENUM ('a', 'b', 'c'); CREATE TYPE postgres=# CREATE DOMAIN abc_domain AS abc_enum; CREATE DOMAIN postgres=# SELECT 'a'::abc_domain = 'a'::abc_domain; ERROR: operator does not exist: abc_domain = abc_domain LINE 1: SELECT 'a'::abc_domain = 'a'::abc_domain; ^ HINT: No operator matches the given name and argument types. You might need to add explicit type casts. This has been already discussed a long time ago, and the idea was rejected at the time since there was no demand for it: https://www.postgresql.org/message-id/flat/BANLkTi%3DaGxDbGPSF043V2K-C2vF2YzGz9w%40mail.gmail.com#da4826d2cbbaca20e3440aadb3093158 Given that we implemented that behaviour for domains over ranges and multiranges, I don't see the harm in doing the same for domains over enums. What do you think ? -- Ronan Dunklau