Why stop at fixing big integers? Attached is the beginnings of a patch (against the below 1.9.2) to correct all integer sizes for all database types.

I only have PostgreSQL to test with, so I only filled in the integer lengths for MySQL implied in the original code. Also, I found the applicable PostgreSQL lengths by comparing a fresh install of 1.9.2+ (Build: 20080725) to an upgrade from 1.8.5+ (Build: 20080507). Notice XMLDB integers with length="9" are neither tested nor written for PostgreSQL here.

Someone can expand this patch with MySQL information, and change the XMLDB action from "Check Bigints" to "Check Integer Lengths."