Android game programming - Heap issues

I work for a small Android game development company, and currently I'm having an issue. I'm running a pretty standard windows 7 x64 machine, with Eclipse and the Android SDK.

Can Sun JVM handle gigantic heap sizes without problems, and how?

I have heard several people claiming that you can not scale the JVM heap size up. I've heard claims of the practical limit being 4 gigabytes (I heard an IBM consultant say that), 10 gigabytes, 32 gigabytes, and so on... I simply can not believe any of those numbers and have been wondering about the issue now for a while.

Why is the maximum size of the Java heap fixed?

It is not possible to increase the maximum size of Java's heap after the VM has started. What are the technical reasons for this? Do the garbage collection algorithms depend on having a fixed amount of memory to work with? Or is it for security reasons, to prevent a Java application from DOS'ing other applications on the system by consuming all available memory?

In PHP, what happens in memory when we use mysql_query

I used to fetch large amount of data using mysql_query then iterating through the result one by one to process the data. Ex:

Detect application heap size in Android

How do you programmatically detect the application heap size available to an Android app?

Detect application heap size in Android

How do you programmatically detect the application heap size available to an Android app?

Android Activity causing Service crash due to heap fragmentation

I have an Android app (activity) which also has a corresponding service. The service is started by the activity and is supposed to run continuously even when the activity is stopped. When the activity is started again it can bind to the service and query it.

DiskStore .throwableSafeExpireElementsIfRequired(620) org.appfuse.model.User Cache: Could not expire elements from disk due to null

I am facing above exception followed by OutOfMemoryException.