Hi, for applications and Timesten databases on the same server we can use direct model to gain the bese performance.
But I want to know that how big heap size of JVM to be set for my java application when enabling direct model?
Does my application need more head memory when direct model than other local communication protocols, such as Unix domain socket or IPC?
Supposing my Timesten database takes 12GB memory from OS, does it mean I need specify the same size for JVM heap(-Xmx12G)?
I hope there are some documents or links about this.
The TimesTen database is always located in a separate shared memory segment regardless of how you connect to it. In client/server mode there is a separate server process that accesses the shared memory on behalf of the application while in direct mode the shared memory segment is mapped into the process address space. The total amount of memory used is the same in both cases (actually slightly less in the direct mode case as you do nto need the sevrer process). Since the memory si allocated as a shared memory segment and not from the Java heap you do not need to increase Java heap size to use direct mode.