Looks no obvious relationship between the partition or tables, maybe try make 
them in different jobs, so they could run at same time to fully make use of the 
cluster resource.




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On 02/27/2020 22:50, Manjunath Shetty H wrote:
Hi Enrico,


In that case how to make effective use of all nodes in the cluster ?.


And also whats your opinion on the below
Create 10 Dataframes sequentially in Driver program and transform/write to hdfs 
one after the other
Or the current approach mentioned in the previous mail 
What will be the performance implications ?


Regards
Manjunath


From: Enrico Minack <m...@enrico.minack.dev>
Sent: Thursday, February 27, 2020 7:57 PM
To:user@spark.apache.org <user@spark.apache.org>
Subject: Re: Convert each partition of RDD to Dataframe
 
Hi Manjunath,


why not creating 10 DataFrames loading the different tables in the first place?


Enrico




Am 27.02.20 um 14:53 schrieb Manjunath Shetty H:

Hi Vinodh,


Thanks for the quick response. Didn't got what you meant exactly, any reference 
or snippet  will be helpful.


To explain the problem more,
I have 10 partitions , each partition loads the data from different table and 
different SQL shard.
Most of the partitions will have different schema.
Before persisting the data i want to do some column level manipulation using 
data frame.
So thats why i want to create 10 (based on partitions ) dataframes that maps to 
10 different table/shard from a RDD.


Regards
Manjunath
From: Charles vinodh <mig.flan...@gmail.com>
Sent: Thursday, February 27, 2020 7:04 PM
To: manjunathshe...@live.com <manjunathshe...@live.com>
Cc: user <user@spark.apache.org>
Subject: Re: Convert each partition of RDD to Dataframe
 
Just split the single rdd into multiple individual rdds using a filter 
operation and then convert each individual rdds to it's respective dataframe.. 


On Thu, Feb 27, 2020, 7:29 AM Manjunath Shetty H <manjunathshe...@live.com> 
wrote:



Hello All,



In spark i am creating the custom partitions with Custom RDD, each partition 
will have different schema. Now in the transformation step we need to get the 
schema and run some Dataframe SQL queries per partition, because each partition 
data has different schema.

How to get the Dataframe's per partition of a RDD?.

As of now i am doing foreachPartition on RDD and converting Iterable<Row> to 
List and converting that to Dataframe. But the problem is converting Iterable 
to List will bring all the data to memory and it might crash the process.

Is there any known way to do this ? or is there any way to handle Custom 
Partitions in Dataframes instead of using RDD ?

I am using Spark version 1.6.2.

Any pointers would be helpful. Thanks in advance





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