I tried removing userid from my sort clause but still the same issue- data not sorted.
var newDf = data.repartition(col(userid)).sortWithinPartitions(sid,time)
I am checking the sorting results by temporary writing this file to Hive as well as HDFS. Now, when I see the user wise data it is not sorted.
Attaching the output file for your reference.
On the basis of sorting within userid partitions, I want to add a flag which marks first item in the partition as true other items in that partition as false.
If my sorting order is disturbed, the flag is wrongly set.
Please suggest what else could be done to fix this very basic scenario of sorting in Spark across multiple partitions across multiple nodes.
Thanks & Regards,
You partition by userid, why do you then sort again by userid in the partition? Can you try to remove userid from the sort?
How do you check if the sort is correct or not?
What is the underlying objective of the sort? Do you have more information on schema and data?
On 4. Jun 2018, at 05:47, Sing, Jasbir <firstname.lastname@example.org> wrote:
We are currently using Spark 2.2.0 and facing some challenges in sorting of data on multiple partitions.
We have tried below approaches:
- Spark SQL approach:
a. var query = "select * from data distribute by " + userid + " sort by " + userid + ", " + time “
This query returns correct results in Hive but not in Spark SQL.
- var newDf = data.repartition(col(userud)).orderBy(userid, time)
- var newDf = data.repartition(col(userid)).sortWithinPartitions(userid,time)
But none of the above approach is giving correct results for sorting of data.
Please suggest what could be done for the same.
Thanks & Regards,
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