Hi, BB Ideally you can do the query like: select key, value.percent from mytable_data lateral view explode(audiences) f as key, value limit 3; But there is a bug in HiveContext: https://issues.apache.org/jira/browse/SPARK-5237 I am working on it now, hopefully make a patch soon.
Cheng Hao -----Original Message----- From: BB [mailto:bagme...@gmail.com] Sent: Friday, January 16, 2015 12:52 AM To: user@spark.apache.org Subject: using hiveContext to select a nested Map-data-type from an AVROmodel+parquet file Hi all, Any help on the following is very much appreciated. ================================= Problem: On a schemaRDD read from a parquet file (data within file uses AVRO model) using the HiveContext: I can't figure out how to 'select' or use 'where' clause, to filter rows on a field that has a Map AVRO-data-type. I want to do a filtering using a given ('key' : 'value'). How could I do this? Details: * the printSchema of the loaded schemaRDD is like so: ------ output snippet ----- |-- created: long (nullable = false) |-- audiences: map (nullable = true) | |-- key: string | |-- value: struct (valueContainsNull = false) | | |-- percent: float (nullable = false) | | |-- cluster: integer (nullable = false) ----------------------------- * I dont get a result when I try to select on a specific value of the 'audience' like so: "SELECT created, audiences FROM mytable_data LATERAL VIEW explode(audiences) adtab AS adcol WHERE audiences['key']=='tg_loh' LIMIT 10" sequence of commands on the spark-shell (a different query and output) is: ------ code snippet ----- scala> val hiveContext = new org.apache.spark.sql.hive.HiveContext(sc) scala> val parquetFile2 = hiveContext.parquetFile("/home/myuser/myparquetfile") scala> parquetFile2.registerTempTable("mytable_data") scala> hiveContext.cacheTable("mytable_data") scala> hiveContext.sql("SELECT audiences['key'], audiences['value'] scala> FROM mytable_data LATERAL VIEW explode(audiences) adu AS audien LIMIT 3").collect().foreach(println) ------ output --------- [null,null] [null,null] [null,null] ------------------------ gives a list of nulls. I can see that there is data when I just do the following (output is truncated): ------ code snippet ----- scala> hiveContext.sql("SELECT audiences FROM mytable_data LATERAL VIEW explode(audiences) tablealias AS colalias LIMIT 1").collect().foreach(println) ---- output -------------- [Map(tg_loh -> [0.0,1,Map()], tg_co -> [0.0,1,Map(tg_co_petrol -> 0.0)], tg_wall -> [0.0,1,Map(tg_wall_poi -> 0.0)], ... ------------------------ Q1) What am I doing wrong? Q2) How can I use 'where' in the query to filter on specific values? What works: Queries with filtering, and selecting on fields that have simple AVRO data-types, such as long or string works fine. =========================== I hope the explanation makes sense. Thanks. Best, BB -- View this message in context: http://apache-spark-user-list.1001560.n3.nabble.com/using-hiveContext-to-select-a-nested-Map-data-type-from-an-AVROmodel-parquet-file-tp21168.html Sent from the Apache Spark User List mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@spark.apache.org For additional commands, e-mail: user-h...@spark.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@spark.apache.org For additional commands, e-mail: user-h...@spark.apache.org