Bad ESQL/C Memory Configuration

I have a problem allocating medium-sized memory when using ESQL-C. Actually, it happens after connecting to my Database: All the Memory I can get is just below 8MB ! Though this is a serious problem considering the amount of Data to be processed and the slowness of connections, I am almost certain, that this is a feature, not a bug. There must be a configuration variable limiting my access to the resource. But where ? The ESQL-C manual is not very informative on the subject. Can someone help me ? There must be lots of programmers here, that must have experienced the same problems, since it came all from using a default configuration and nothing I can think of does change it. Thanks in advance! For Information: I'm running program and server on the same Machine, Sun UltraSparc with Solaris 2.5.1 and 512 MB RAM (and plenty of real and virtual memory free while running) with Informix Online Server 7.24 UC2. I' us onipcshm to connect, but couldn't find any Shared memory parameter to affect this.