On 30 Aug, 2006, at 15:22, Andi Vajda wrote:
On Wed, 30 Aug 2006, Phillip J. Eby wrote:
We could do that, after we got rid of any existing code that
depends on the old semantics of enumerations.
I could rename the old enumeration to StringEnumeration and
introduce a new enum that behaves like what Grant is suggesting.
However, it should be noted that this may lead to interesting
problems in schema upgrades. My understanding is that the reason
for wanting explicit values (as opposed to simple sequence) is
that it allows constant values to be preserved across releases,
even if things are added or removed. Second, it allows the use of
enumerations as constants for interacting with external systems,
like socket mode flags and such.
I should dispell any rumors of constant-ness across schema changes.
The value that gets persisted for a new type of enum value is the
position of the constant in the sorted-by-constant-name constant
list. If someone renames a constant or inserts one alphabetically,
that's a schema change.
I think PJE was talking about the dump-and-reload schema upgrade
strategy: Presumably, we would store the .value for that.
--Grant
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