title: java : How to use heap beyond 4 GB memory in 32 bit JVM
body: <p>We have a product that runs currently on a 32 bit 1.6 JRE. We're using Berkeley DB which consumes about 2.5 GB RAM of the 4 GB address space. That leaves us about 750 MB of memory for the JVM address space.</p>
  
  <p>We're currently hitting OutOfMemory issues with the current setup. It would be nice to increase our JVM heap size to 1.5 GB while still retaining Berkeley DB's 2.5 GB space. Is there any way to access more than 4 GB RAM/heap in a 32-bit JVM ? I've considering the following solutions<br>
  1) use a JVM which does better GC -- this will give me marginal results -- I could get about 50-100 MB working memory <br>
  2) something like memcached or "out of process ehcache " -- this can get me as much as the hardware allows with the overhead of IPC/serialization.</p>
  
  <p>Are there other solutions to increasing an application's addressable memory ? </p>
  
  <p>The solution should work on solaris 10 running sparc.</p>
  
  <p>*<em>UPDATE : Because of using native shared libraries, right now, we're unable to switch to a 64-bit JVM even though the OS is 64-bit *</em></p>
  
  <p>thank you,</p>