Heap dump is getting generated using OCI calls

There is a backend application service which continuously keeps runs at the server. There are many requests sent to this service which inturn usesOCI or PROC submodules to process the request. The heap memory continuously keep increasing though all the dynamic allocations made and thehandles are freed. So could any one please carify..

1> Is there any benefit of changing ProC calls to OCI calls ? Will this effect/ help in reducing the heap size ?

2> Is there any other OCI APIs available to release the used handles, apart from the freeing statement handle and error handle ?

3> Though all the handles are cleared using OCIHandleFree(), memory in the heap does not come down because of which new processes allocates new memory , Why is it so ?