Mapreduce

我在做MR的時候想把結果寫入一個新集合中,其實之前也有做過,但是在我印像中好像總是寫不進去啊,摔!

//....more code
        try {
            cmd = new MapReduceCommand(
              this.dbc, MapString,
              ReduceString,
              dbtemp,
              MapReduceCommand.OutputType.REPLACE,
              query);

            cmd.setFinalize(Finalize);
            output = this.dbc.mapReduce(cmd);
        }
//...more code

MapReduceCommand 的形參如下

 public MapReduceCommand(com.mongodb.DBCollection inputCollection, java.lang.String map, java.lang.String reduce, java.lang.String outputCollection, com.mongodb.MapReduceCommand. OutputType type, com.mongodb.DBObject query) { /* compiled code */ }

希望有做過mongo的朋友一起討論討論