Tom Dunstan <[EMAIL PROTECTED]> writes:
> Andrew Dunstan wrote:
>> I'm inclined to say let's keep it simple and stay with a fixed 4-byte 
>> global size.

> Fair enough. I'm ok with 4 bytes; 8 seemed a bit gratuitous.

If you're gonna fix it at 4 bytes, then I strongly suggest that the
value identifiers actually be OIDs assigned through the standard
OID-generating mechanism, and that the pg_enum table have the structure

        standard system OID column      unique enum-value identifier
        enumtypid                       OID of enum type it belongs to
        enumname                        name of enum value

unique indexes on:
        (enumtypid, enumname)

The advantage of doing this is that you can use the existing, well
debugged, normally-quite-fast mechanisms for generating new unique value
identifiers.  Rather than consing up your own slow full-table-scan
mechanism as envisioned in the original proposal.

                        regards, tom lane

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