Peter Eisentraut wrote:
An objection to enums on the ground that foreign keys can accomplish the
same thing could be extended to object to any data type with a finite
domain.
Exactly. The extreme case is the boolean type, which could easily be
represented by a two-value enum. Or, if you were feeling masochistic, a
FK to a separate table. Which is easier?
People regularly do stuff like having domains over finite text values,
or having a FK to a separate (static) table, or using some sort of EAV.
Enums are type-safe, easily ordered, relatively efficient and don't
leave zillions of little static tables all over the place, a combination
of attributes that none of the alternative solutions in this space present.
Cheers
Tom
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
