Performance tuning using copy

Hi,

 

     I have to know why does copy commands work faster as compared to the insert commands. The thing is that i have a lot of constraints and triggers. I know insert will check all the triggers and constraints, but i wonder if copy will also do it and then if it does then this has also to be slow. But copy loads the database very fast. Can u tell me why.

 

     I also have a concern about the performace tuninig while updating the database. Can some one suggest me to tune in more than the use of copy command. I have tried to even disable the triggers and constraints but what I get is only minimal gain. Is there any other mechanism by which we can do faster updations.

 

Regards,

Sid