The pg_enum catalog contains entries matching enum types to their associated values and labels. The internal representation of a given enum value is actually the OID of its associated row in pg_enum. The OIDs for a particular enum type are guaranteed to be ordered in the way the type should sort, but there is no guarantee about the ordering of OIDs of unrelated enum types.
Table 44-17. pg_enum Columns
|enumtypid||oid||pg_type.oid||The OID of the pg_type entry owning this enum value|
|enumlabel||name||The textual label for this enum value|