Authorize.Net Transaction IDs to increase in size
By Dan Collis-Puro
September 2, 2008
A sign of their success, Authorize.net is going to break through Transaction ID numbers greater than 2,147,483,647 (or 2^31), which happens to exceed the maximum size of a signed MySQL int() column and the default Postgres “integer”.
It probably makes sense to ensure that your transaction ID columns are large enough proactively—this would not be a fun bug to run into ex-post-facto.