I could , but only if I had it beforehand. I do not know what the dataframe is until I pass the query parameter and receive the resultant dataframe inside the iteration.
The steps are : Original DF -> Iterate -> Pass every element to a function that takes the element of the original DF and returns a new dataframe including all the matching terms From: Andrew Melo <andrew.m...@gmail.com> Sent: Friday, December 28, 2018 8:48 PM To: em...@yeikel.com Cc: Shahab Yunus <shahab.yu...@gmail.com>; user <user@spark.apache.org> Subject: Re: What are the alternatives to nested DataFrames? Could you join() the DFs on a common key? On Fri, Dec 28, 2018 at 18:35 <em...@yeikel.com <mailto:em...@yeikel.com> > wrote: Shabad , I am not sure what you are trying to say. Could you please give me an example? The result of the Query is a Dataframe that is created after iterating, so I am not sure how could I map that to a column without iterating and getting the values. I have a Dataframe that contains a list of cities for which I would like to iterate over and search in Elasticsearch. This list is stored in Dataframe because it contains hundreds of thousands of elements with multiple properties that would not fit in a single machine. The issue is that the elastic-spark connector returns a Dataframe as well which leads to a dataframe creation within a Dataframe The only solution I found is to store the list of cities in a a regular scala Seq and iterate over that, but as far as I know this would make Seq centralized instead of distributed (run at the executor only?) Full example : val cities = Seq("New York","Michigan") cities.foreach(r => { val qb = QueryBuilders.matchQuery("name", r).operator(Operator.AND) print(qb.toString) val dfs = sqlContext.esDF("cities/docs", qb.toString) // Returns a dataframe for each city dfs.show() // Works as expected. It prints the individual dataframe with the result of the query }) val cities = Seq("New York","Michigan").toDF() cities.foreach(r => { val city = r.getString(0) val qb = QueryBuilders.matchQuery("name", city).operator(Operator.AND) print(qb.toString) val dfs = sqlContext.esDF("cities/docs", qb.toString) // null pointer dfs.show() }) From: Shahab Yunus <shahab.yu...@gmail.com <mailto:shahab.yu...@gmail.com> > Sent: Friday, December 28, 2018 12:34 PM To: em...@yeikel.com <mailto:em...@yeikel.com> Cc: user <user@spark.apache.org <mailto:user@spark.apache.org> > Subject: Re: What are the alternatives to nested DataFrames? Can you have a dataframe with a column which stores json (type string)? Or you can also have a column of array type in which you store all cities matching your query. On Fri, Dec 28, 2018 at 2:48 AM <em...@yeikel.com <mailto:em...@yeikel.com> > wrote: Hi community , As shown in other answers online , Spark does not support the nesting of DataFrames , but what are the options? I have the following scenario : dataFrame1 = List of Cities dataFrame2 = Created after searching in ElasticSearch for each city in dataFrame1 I've tried : val cities = sc.parallelize(Seq("New York")).toDF() cities.foreach(r => { val companyName = r.getString(0) println(companyName) val dfs = sqlContext.esDF("cities/docs", "?q=" + companyName) //returns a DataFrame consisting of all the cities matching the entry in cities }) Which triggers the expected null pointer exception java.lang.NullPointerException at org.elasticsearch.spark.sql.EsSparkSQL$.esDF(EsSparkSQL.scala:53) at org.elasticsearch.spark.sql.EsSparkSQL$.esDF(EsSparkSQL.scala:51) at org.elasticsearch.spark.sql.package$SQLContextFunctions.esDF(package.scala:37) at Main$$anonfun$main$1.apply(Main.scala:43) at Main$$anonfun$main$1.apply(Main.scala:39) at scala.collection.Iterator$class.foreach(Iterator.scala:742) at scala.collection.AbstractIterator.foreach(Iterator.scala:1194) at org.apache.spark.rdd.RDD$$anonfun$foreach$1$$anonfun$apply$28.apply(RDD.scala:921) at org.apache.spark.rdd.RDD$$anonfun$foreach$1$$anonfun$apply$28.apply(RDD.scala:921) at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2067) at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:2067) at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87) at org.apache.spark.scheduler.Task.run(Task.scala:109) at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:345) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) 2018-12-28 02:01:00 ERROR TaskSetManager:70 - Task 7 in stage 0.0 failed 1 times; aborting job Exception in thread "main" org.apache.spark.SparkException: Job aborted due to stage failure: Task 7 in stage 0.0 failed 1 times, most recent failure: Lost task 7.0 in stage 0.0 (TID 7, localhost, executor driver): java.lang.NullPointerException What options do I have? Thank you. -- It's dark in this basement.
