Hi,
aggregate performs an in-place aggregation, i.e., the input and output type of
aggregate() is identical, but the aggregated fields are updated.
Causion: All fields that are not associated with an aggregation function and
are not not a grouping field have non-deterministic values. That means as well,
that you cannot apply more than one aggregation function for each fields (e.g.,
computing min and max for the same field is not possible with aggregate())
Best, Fabian
From: Michele Bertoni
Sent: Wednesday, 8. July, 2015 10:06
To: user@flink.apache.org
hi, you are not printing the aggregation but the input
val result = orders.aggregate(Aggregations.MAX, 2)
result.print
cheers
michele
> Il giorno 08/lug/2015, alle ore 02:00, hagersaleh <loveallah1...@yahoo.com>
> ha scritto:
>
> why when use orders.aggregate(Aggregations.MAX, 2) not return one value but
> return more value
>
> ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
> DataSet<Orders> orders=(DataSet<Orders>)
> env.readCsvFile("/home/hadoop/Desktop/Dataset/orders.csv")
> .fieldDelimiter('|')
> .includeFields(mask).ignoreFirstLine()
> .tupleType(get_Order().getClass());
> orders.aggregate(Aggregations.MAX, 2) ;
>
> orders.print();
>
> orders.writeAsCsv("/home/hadoop/Desktop/Dataset/join_instead_of_optmization",
> "\n", "|",WriteMode.OVERWRITE);
> env.execute();
>
> out put
> 1> (280866,129457,96048.38)
> 1> (280867,16568,89875.17)
> 1> (280868,47827,118013.89)
> 1> (280869,104143,220415.76)
> 1> (280870,105512,262166.76)
> 1> (280871,36244,123478.83)
> 1> (280896,148177,92956.99)
> 1> (280897,83611,128889.07)
> 1> (280898,29863,289893.15)
> 1> (280899,143962,111581.46)
> 1> (280900,43577,26781.38)
> 1> (280901,87340,30915.09)
> 1> (280902,6769,235803.72)
> 1> (280903,61471,138553.46)
> 1> (280928,69407,168763.3)
> 1> (280929,114457,5392.93)
> 1> (280930,58939,47427.22)
> 1> (280931,110210,125524.13)
> 1> (280932,91751,11434.53)
>
>
>
> --
> View this message in context:
> http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/why-when-use-orders-aggregate-Aggregations-MAX-2-not-return-one-value-but-return-more-value-tp1977.html
> Sent from the Apache Flink User Mailing List archive. mailing list archive at
> Nabble.com.
