CODEWITHSUNDEEP
apache-pig
USB
USB

Reputation: 6139

Unable to open iterator for alias while using CONCAT

Trying to split a column from originaldata and need to join back. For that I created a rowid along with originaldata and seperated a col from originaldata along with concatenating the rowid 

originaldata = load '$input' using PigStorage('$delimiter');
rankedoriginaldata = rank originaldata;
numericdata = foreach rankedoriginaldata generate CONCAT($0,$split);

But I am not able to do this statement

numericdata = foreach rankedoriginaldata generate CONCAT($0,$split);

Command

pig -x local -f seperator.pig -param input=data/StringNum.csv -param output=OUT/Numericfile -param delimiter="," -param split='$3'

It shows the following stack tree

Pig Stack Trace
---------------
ERROR 1066: Unable to open iterator for alias numericdata

org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: Unable to open iterator for alias numericdata
    at org.apache.pig.PigServer.openIterator(PigServer.java:838)
    at org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:696)
    at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:320)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:194)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:170)
    at org.apache.pig.tools.grunt.Grunt.exec(Grunt.java:84)
    at org.apache.pig.Main.run(Main.java:475)
    at org.apache.pig.Main.main(Main.java:157)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:208)
Caused by: java.io.IOException: Job terminated with anomalous status FAILED
    at org.apache.pig.PigServer.openIterator(PigServer.java:830)
    ... 12 more
================================================================================

But when I did

numericdata = foreach originaldata generate CONCAT($0,$split);

I am getting the expected output.

Doubt: While loading a data do the order of tuple change? If we are loading a data say

1,4,6
3,8,9
2,4,5

How will be the ordering whether it shuffles like

1,6,4
8,9,3...

Upvotes: 1

Views: 432

Answers (1)

Frederic
Frederic

Reputation: 3284

Try casting your arguments for CONCAT to chararray first:

numericdata = foreach originaldata generate CONCAT((chararray)$0,(chararray)$split);

I think the cast is necessary because CONCAT expects two chararrays. RANK however produces a Long (which you pass as $0 to CONCAT).

Concerning your doubt: order of fields in your tuples is not going to change. The order of tuples in the relation may change however.

Upvotes: 2

Related Questions