Long MRP run time

We’re running AX 2009 here, and normally when my user runs an MRP job (Master Planning → Master Scheduling) it will take about 20 minutes. Recently, it’s been taking about an hour to complete now.

I searched around on the Internet and I saw references to a fragment database, so I defragged the database as best as I could but the job is still taking the same amount of run time. I’m currently running a consistency check but do not have the results yet.

I’m fairly new to AX, so I’m not sure what else to check or how to troubleshoot the issue. Any help is greatly appreciated. Thanks in advance.