>> Thoughts? > > enum types exist as an optimisation-by-avoidance of referential > integrity. > > We're a relational database, so IMHO we should spend time performance > tuning RI.
I take the view that they exist as a way of representing enumerations of application/domain values - if it's hard coded in the application, it's hard coded in the database by using an enum. This is why it isn't that big a problem that they cannot be amended - they ought to be very static, immutable values in the first place. I still think it would be handy to be able to append new values though, and not have to ALTER COLUMN USING to a new enum type. Besides, using enums in place of lookup tables doesn't really make much sense as an optimisation. It's very cool to be able to write queries like SELECT * FROM payments WHERE payment_type = 'cash', rather than having to recall time and again what the PK of cash is within your lookup table. -- Regards, Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
