Database error frequently, help please...

[coolphim]

Hello,
Recently, my site is down many times in a day. I contacted the host supporter and they said that there were too many query from my site ( which is around 200 users online in my forum). They suggested me to use arrays of database user which can fix the problem. Please help me to do it because i really dont want to lose my customers. THANKS

Ps: Below is my chat log between me and my host supporter, plz take a look for more understanding. (Samuel is my host supporter)

Samuel P.: I have fix it for you.
Anh: so everytime it's down, i have to ask somebody to fix it?
Anh: it's been down so frequently that makes my site loses customers
Samuel P.: Presently we have set max limit(no of requests) on our server as 50000 per hour.
Samuel P.: Your database user is crossing the max question limit.
Samuel P.: You can solve it by recreating your database user.
Samuel P.: But it would be the temporary fix.
Samuel P.: There's a permanent solution for this that you can use arrays of database user.
Anh: can you show me how to use arrays of database user
Samuel P.: I'm sorry, you have to contact your web coding developer.