We are in the middle of a huge OWB migration (10.1 to 11gR2). There is about 1 Gb of MDL’s. During the migration we noticed that the Design Center became very very slow on opening. (7 minutes for the screen).
Luckily our DBA did pay attention in class. He pointed out the magic button Tools >> Optimize Repository.
This brought the opening back to 3 seconds.
Till Next Time