Unable to open iterator for alias while using CONCAT - apache-pig

Question

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...

Answer 1

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.