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From Riccardo Ferrari <ferra...@gmail.com>
Subject Re: Is there an operation to create multi record for every element in a RDD?
Date Wed, 09 Aug 2017 08:54:03 GMT
Depends on your Spark version, have you considered the Dataset api?

You can do something like:

val df1 = rdd1.toDF("userid")

val listRDD = sc.parallelize(listForRule77)

val listDF = listRDD.toDF("data")

df1.crossJoin(listDF).orderBy("userid").show(60, truncate=false)

+------+----------------------+

|userid|data                  |

+------+----------------------+

|1     |1,1,100.00|1483891200,|

|1     |1,1,100.00|1483804800,|

...

|1     |1,1,100.00|1488902400,|

|1     |1,1,100.00|1489075200,|

|1     |1,1,100.00|1488470400,|

...

On Wed, Aug 9, 2017 at 10:44 AM, Ryan <ryan.hd.ren@gmail.com> wrote:

> It's just sort of inner join operation... If the second dataset isn't very
> large it's ok(btw, you can use flatMap directly instead of map followed by
> flatmap/flattern), otherwise you can register the second one as a
> rdd/dataset, and join them on user id.
>
> On Wed, Aug 9, 2017 at 4:29 PM, <luohui20001@sina.com> wrote:
>
>> hello guys:
>>       I have a simple rdd like :
>> val userIDs = 1 to 10000
>> val rdd1 = sc.parallelize(userIDs , 16)   //this rdd has 10000 user id
>>       And I have a List[String] like below:
>> scala> listForRule77
>> res76: List[String] = List(1,1,100.00|1483286400, 1,1,100.00|1483372800,
>> 1,1,100.00|1483459200, 1,1,100.00|1483545600, 1,1,100.00|1483632000,
>> 1,1,100.00|1483718400, 1,1,100.00|1483804800, 1,1,100.00|1483891200,
>> 1,1,100.00|1483977600, 3,1,200.00|1485878400, 1,1,100.00|1485964800,
>> 1,1,100.00|1486051200, 1,1,100.00|1488384000, 1,1,100.00|1488470400,
>> 1,1,100.00|1488556800, 1,1,100.00|1488643200, 1,1,100.00|1488729600,
>> 1,1,100.00|1488816000, 1,1,100.00|1488902400, 1,1,100.00|1488988800,
>> 1,1,100.00|1489075200, 1,1,100.00|1489161600, 1,1,100.00|1489248000,
>> 1,1,100.00|1489334400, 1,1,100.00|1489420800, 1,1,100.00|1489507200,
>> 1,1,100.00|1489593600, 1,1,100.00|1489680000, 1,1,100.00|1489766400)
>>
>> scala> listForRule77.length
>> res77: Int = 29
>>
>>       I need to create a rdd containing  290000 records. for every userid
>> in rdd1 , I need to create 29 records according to listForRule77, each
>> record start with the userid, for example 1(the
>> userid),1,1,100.00|1483286400.
>>       My idea is like below:
>> 1.write a udf
>> to add the userid to the beginning of every string element
>> of listForRule77.
>> 2.use
>> val rdd2 = rdd1.map{x=> List_udf(x))}.flatmap()
>> , the result rdd2 maybe what I need.
>>
>>       My question: Are there any problems in my idea? Is there a better
>> way to do this ?
>>
>>
>>
>> --------------------------------
>>
>> Thanks&amp;Best regards!
>> San.Luo
>>
>
>

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