Get 1 element of DataSet

[Vinh June]

Hi,

Is there any way to get 1 element of a DataSet, for example:
----------------------------------------
val stringSet: DataSet[String] = ...
val str: String = stringSet.getFunction()
str
----------------------------------------

[Stefan Bunk]

Hi Vinh,

have a look at the first function: http://flink.apache.org/docs/0.8/dataset_transformations.html#first-n

Stefan

On 5 February 2015 at 15:14, Vinh June <[hidden email]> wrote:

Hi,

Is there any way to get 1 element of a DataSet, for example:
----------------------------------------
val stringSet: DataSet[String] = ...
val str: String = stringSet.getFunction()
str
----------------------------------------



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[Vinh June]

Hi Stefan,

DataSet.first(n) produces a child DataSet, while I need the element

Specifically, I have a CSV with header line and I want to make the maps of each (header,value) pair for each line

[Fabian Hueske-2]

Have a look at "broadcast values/sets".

Not sure if that solves you problem, but you could do:

DataSet<String> stringSet = ...

DataSet<String> first = stringSet.first();

DataSet myNewSet = stringSet.map(myMapFnc).withBroadcastSet(first,"first value");

This distributes the first DataSet to all Mapper functions and you can read and use the value.

Cheers, Fabian

2015-02-05 15:34 GMT+01:00 Vinh June <[hidden email]>:

Hi Stefan,

DataSet.first(n) produces a child DataSet, while I need the element

Specifically, I have a CSV with header line and I want to make the maps of
each (header,value) pair for each line



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