Some background for this is:

https://hg.python.org/tracker/roundup/rev/eb3be57f1ef2

which is a patch at the templating level

or this patch that applies to rdbms_common.py

https://hg.python.org/tracker/roundup/rev/1548763e8273

but this patch returns id 0. I think it should return a value error
exception.

The Link type is declared as a SQL INTEGER which is 2^31-1 for both
mysql and postgres. SqLite's value is higher (up to 8 bytes) and python
should be able to int(8), but limiting it to the size of int(4) is
reasonable at this point.

It does impose a maximum of 2,147,483,647 items of any type in the rdbms
database.