Cedric Berger wrote:
>>> 1) What is the easiest way to get that directly in C?
>>
>> The usual locution is "get_database_name(MyDatabaseId)".
>
> Ok, but then how do I find "MyDatabaseId" in, say,
> a BeginForeignScan() or GetForeignRelSize() FDW callback?
It is a global, all you should have to do is
#include "miscadmin.h"
Yours,
Laurenz Albe