Evictor performance question

xdm

I using freeze evictor for persitence of a tree like structure, but same nodes not all can have millon of childs or more.

now i have samething like this

clas BaseItem
{
          string title;
}

dictionary<Ice::Identity,BaseItem*> ItemMap;

class Item extends BaseItem
{
       string content;
}

interface NodeAdmin
{
   BaseItem* add(BaseItem* obj);
   BasetIem* get(Ice::Identity id);
}

class Node extends BaseItem implementes NodeAdmin
{
     ItemMap childs;
}

can evictor and this design have a good performance or is better store childs as a separte FreezeMap for each Node.

And the second option implique have millon of database files because same node can have a millon of child nodes each one with is dedicated FreezeMap and db, i'm not sure if this is a good idea.

i special interesting in performance of get method. is the most invoked all the time system is up.
any help is apreciate thanks

bernard

Hi Jose,

Ideally the objects (servants) stored in a Freeze Evictor should be of average size. Lots of very small objects waste disk space since the Freeze Evictor adds overhead to each record. With a very large object, like an object holding an Ice dictionary with a million entries, the problem is that each little change in that object will result in the entire object being written to disk.

So, I'd recommend to use a Freeze dictionary to hold your items, since they can be so numerous. And I don't see why all your nodes can't share the same Freeze dictionary.

Also this interface:

interface NodeAdmin
{
   BaseItem* add(BaseItem* obj);
   BasetIem* get(Ice::Identity id);
};

does not make much sense, since BaseItem has no operation. Maybe you meant to return BaseItem by value.

Cheers,
Bernard