phrase merge Issue

When I tried to do phrase merge by selecting 100ks of phrases , the system gave me dump message . What is the best way to do merge at once when you have huge data . Also while merging there is option to do check mark for OT and there is no button to select at once this OT field for all phrases to merge . Do I have to click this box 1000 times or is there any easy way to handle this ?

Regards,

K G