code: function put(position, id, value, callback){
  		var newKey = encodeLevelKey(position, id);
  		// look up old key
  		idToKey(id, function(err, oldKey){
  
  			var batch = [];
  
  			// add the main update to the batch
  			batch.push({type:"put", key:"geos~" + newKey, value:value});
  			if (oldKey){
  				// remove the old key 
  				batch.push({type:"del", key:"geos~" + oldKey});	
  			}
  			// update the pointer
  			batch.push({type:"put", key:"keys~" + id, value:newKey});	
  
  			db.batch(batch, function (err) {
  				if (callback){
  					callback(err);
  				}
  			});
  
  
  		});
  		
  	}
docs: /* SLOw