disadvantage on synchronous proxy compared to asynchronous proxy

Hi friends,

Please tell me any disadvantage on Synchronous Proxy compared to asynchronous proxy.

My integration JDBC to PROXY and PROXY to JDBC. Inspite of using the proxy in syn mode i have used asyn proxy, now i have to give the proper answer y i have used asyn proxy, so please give me any drawbacks of syn proxy.

Thanks in advace

Karthikeyan