Is a larger cache always better for JE?
In general, JE performs best when its working set fits within cache. But due to the interaction of Java garbage collection and JE, there can be scenarios when JE actually performs better with a smaller cache. JE caches items by keeping references to database objects. To keep within the memory budget mandated by the cache size, JE will release references to those objects and they will be garbage collected by the JVM. Many JVMs use an approach called generational garbage collection. Objects are categorized by age in order to apply different collection heuristics. Garbage collecting items from the younger space is cheaper and is done with a “partial GC” pass while longer-lived items require a more expensive “Full GC”. If the application tends to access data records that are rarely re-used, and the JE cache has excessive capacity, the JE cache will become populated with data records that are no longer needed by the application. These data records will eventually age and the JVM will re-cat
