Hi, I'm working on a FDW for the unix/linux user database - think /etc/passwd and /etc/group although I'm actually using system calls that could be quietly redirected to LDAP or other backends. It's easy to create the FDW and a table associated with it, something like
CREATE TABLE passwd (
name text,
passwd text,
uid int,
...
The problem is the user could decide to reorder or remove columns so I can't make the assumption that values[0] is always going to be the username.
I have a solution that requires looking at the rel, extracting the atts, and then doing a loop where I check the attname against all possible values for each column. Anything that doesn't match is set to null. This isn't too bad here but it would be a pain if there are many columns.
Is there a cleaner way? I've looked at a number of other FDW implementations but they are generally mapping columns to columns (so it's a short bit of lookup code inside the loop), not copying data provided by a system call.
Thanks,
Bear
