Hello All,

I am programming something which requires a lot of data to be kept in memory for the VF page. And, I am keeping that data in Map.

A button from the page causes this Map to be re-initiated, i.e., to be re-filled. 

Now, when I fill the map the first time, it eats up 90% of my heap space. And, to fill it next time, I have to empty it first.., or force it to be garbage collected. 

Here is what I have tried :

System.debug('Heap Size 0.1: ' + Limits.getHeapSize() + ' , ' + Limits.getLimitHeapSize()); MainMap = new Map<ID, List<MyClass>>(); System.debug('Heap Size 0.2: ' + Limits.getHeapSize() + ' , ' + Limits.getLimitHeapSize()); MainMap = null; System.debug('Heap Size 0.3: ' + Limits.getHeapSize() + ' , ' + Limits.getLimitHeapSize()); MainMap = new Map<ID, List<MyClass>>(); System.debug('Heap Size 0.4: ' + Limits.getHeapSize() + ' , ' + Limits.getLimitHeapSize());

And, here is the output it produces:

Heap Size 0.1: 937950 , 1000000 Heap Size 0.2: 929766 , 1000000 Heap Size 0.3: 929758 , 1000000 Heap Size 0.4: 929766 , 1000000

  As you can see, the heap size is not getting reduced at all, which means I cannot fill the collection again !!

Any pointers or ideas on how I should force this Map to be garbage collected / free up some memory ?

Help would be greatly appreciated !!