Hi,
Below are list of tuples generated by a UDF.
( ( [stdout#{ (day, age, name, address, ['k1#v1','k2#v2'] ) } ] ) )
( ( [stdout#{ (12/2,22,deepak,newyork, ['k1#v2','k2#v2'] ) } ] ) )
( ( [stdout#{ (12/3,22,deepak,newyork, ['k1#v1','k2#v2'] ) } ] ) )
group a -- ( v1 , { (day, age, name, address, ['k1#v1','k2#v2'] ), (12/3,22,
deepak,newjersy, ['k1#v1','k2#v2']) } )
group b -- ( v2 , { (12/2,22,deepak,newyork, ['k1#v2','k2#v2'])} )
I need to run group by on k1 so that i have two groups.
*
Approach #1*
grped = group inputTuples by $0.$0.#'stdout'.$0.$0.$5#'k1'
Error:
2011-03-29 15:16:44,589 [main] WARN org.apache.pig.PigServer - Encountered
Warning IMPLICIT_CAST_TO_MAP 1 time(s).
2011-03-29 15:16:44,589 [main] INFO
org.apache.pig.tools.pigstats.ScriptState - Pig features used in the script:
GROUP_BY
2011-03-29 15:16:44,589 [main] INFO
org.apache.pig.backend.hadoop.executionengine.HExecutionEngine -
pig.usenewlogicalplan is set to true. New logical plan will be used.
2011-03-29 15:16:44,593 [main] ERROR org.apache.pig.tools.grunt.Grunt -
ERROR 2042: Error in new logical plan. Try -Dpig.usenewlogicalplan=false.
Details at logfile:
/home/deepakkv/pigtemp/testworkflow/pig_1301391996435.log
*Approach #2*
As a result i flattened inputTulpes as follows
flat = foreach inputTuples generate flatten($0.$0#'stdout');
(day, age, name, address, ['k1#v1','k2#v2'] )
(12/2,22,deepak,newyork, ['k1#v2','k2#v2'] )
(12/3,22,deepak,newyork, ['k1#v1','k2#v2'] )
So now as i need to group on k1 which is present in a map that is the 5th
item (4 index) i
grped = group flat by $4#'k1';
Error
2011-03-29 15:25:28,459 [main] INFO org.apache.pig.Main - Logging error
messages to: /home/deepakkv/pigtemp/testworkflow/pig_1301392528456.log
2011-03-29 15:25:28,554 [main] INFO
org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting
to hadoop file system at: file:///
2011-03-29 15:25:28,750 [main] ERROR org.apache.pig.tools.grunt.Grunt -
ERROR 1000: Error during parsing. Out of bound access. Trying to access
non-existent column: 4. Schema {bytearray} has 1 column(s).
Details at logfile:
/home/deepakkv/pigtemp/testworkflow/pig_1301392528456.log
*Approach #3*
As i result i tried
grped = group flat by $0.$4#'k1';
Error:
2011-03-29 15:27:18,081 [Thread-13] WARN
org.apache.hadoop.mapred.LocalJobRunner - job_local_0001
java.lang.ClassCastException: java.lang.String cannot be cast to
org.apache.pig.data.Tuple
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POProject.getNext(POProject.java:392)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:276)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POProject.getNext(POProject.java:138)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POProject.getNext(POProject.java:276)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POCast.getNext(POCast.java:916)
How can i group tuples on group id which is present inside a Tuple -> Bag ->
Map -> Tuple (Given key) -> 4thItem (Is a Map again) -> Key
Regards,
Deepak
