So you've updated some tables used in a cube by increasing a column's length. When you go to process the cube you are getting an error like "Errors in the back-end database access module. The size specified for a binding was too small, resulting in one or more column values being truncated."
Seems easy enough, right? You just need to increase the Dimension Attribute's length. Make sure you do it for both the NameColumn and KeyColumns sections:
Thanks to http://shahfaisalmuhammed.blogspot.com/2012/03/size-specified-for-binding-too-small.html