public int compareTo(Table t){	
		/* 
		 compare tables base on temperature
		 double ret = (double) t.tableSize / (double) t.numTxn - (double) tableSize / (double) numTxn;
		*/		
		
		// compare tables base on numTxn "descending order"
		double ret = (double) t.numTxn - (double) numTxn;
		return (ret > 0)? 1 :
			(ret < 0)? -1 : 0; 
	}