Re: Create collation reporting the ICU locale display name

"Daniel Verite" <daniel(at)manitou-mail(dot)org> writes:
> Tom Lane wrote:
>> I think that's a useful function, but it's a different function from
>> the one first proposed, which was to tell you the properties of a
>> collation you already installed (which might not be ICU, even).
>> Perhaps we should have both.

> The pre-create use case would look like:
> SELECT * FROM describe_collation(locale_string text, collprovider "char")

> Post-creation, one could do:
> SELECT * FROM describe_collation(collcollate, collprovider)
> FROM pg_catalog.pg_collation WHERE oid = :OID;

> Possibly it could exists as SELECT * FROM describe_collation(oid)
> but that's essentially the same function.

The advantage of describe_collation(oid) is that we would not be
building knowledge into the callers about which columns of pg_collation
matter for this purpose. I'm not even convinced that the two you posit
here are sufficient --- the encoding seems relevant, for instance.

regards, tom lane