Craig Ringer <craig@2ndquadrant.com> writes:
> On 26 April 2016 at 14:06, 陈天舟 <tianzhouchen@gmail.com> wrote:
>> (1) Since each protocol buffer column requires a schema. I am not sure
>> where is the best place to store that schema info. Should it be in a
>> CONSTRAINT (but I am not able to find the doc referring any custom
>> constraint), or should it be in the COMMENT or somewhere else?
> I can't really imagine how you'd do that without adding a new catalog like
> we have for enum members. A typmod isn't sufficient since you need a whole
> lot more than an integer, and typmods aren't tracked throughout the server
> that well.
> That'll make it hard to do it with an extension.
PostGIS manages to reference quite a lot of schema-like information via
a geometry column's typmod. Maybe there's a reason why their approach
wouldn't be a good fit for this, but it'd be worth investigating.
regards, tom lane
