Insert columns with Ironpython never completes on large data set, Using the GUI it works.

I have an ironpython script that joins and pivots a few data tables and works fine on small to medium sized tables. On larger tables 115 columns and 2.5 million rows the script hangs on the last join. Doing the same operation in spotfire using the GUI works on the same data set. 

I'm using spotfire 7.12 and in Ironpython i'm using the DataTable.AddColumns Method I have tried executing the script in a transaction and not in a transaction both hang on creating the last join with large data. Is there something I can do different in the script to complete the operation like when using the GUI in spotfire?