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An aggregation operations adds up the values of a number of objects. When executing such an operation in RAMCloud three questions, among others, are of interest:1)

1. Where to execute the aggregation operation (client or server side)?

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1. How to describe the range of objects which should be included in the operation?

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1. How to interpret the objects themselves?

The experiments below are centered around the question about where to execute execute the operation. Three different scenarios are implemented:

• Client-side aggregation

for(uint64_t i = 0; i < range; ++i)
   {
        LogEntryHandle handle = objectMap.lookup(tableId, i);
        const Object* obj = handle->userData<Object>();
        int *p;
        p = (int*) obj->data;
        sum += (uint64_t)*p;
   }

/**
* Aggregation Callback
*/
void
aggregateCallback(LogEntryHandle handle, uint8_t type,
                      void *cookie)
{
        const Object* obj = handle->userData<Object>();
        MasterServer *server = reinterpret_cast<MasterServer*>(cookie);

        int *p;
        p = (int*) obj->data;
        server->sum += (uint64_t)*p;
}

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