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Pig, mail # user - Pig Avrostorage Issue regarding Schema evaluation


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Milind Vaidya 2013-01-09, 14:49
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Cheolsoo Park 2013-01-09, 18:26
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Russell Jurney 2013-01-09, 19:25
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Re: Pig Avrostorage Issue regarding Schema evaluation
Cheolsoo Park 2013-01-09, 22:15
Hi Russell,

You're absolute right. Jackson is not needed. Thanks for point that out!

Cheolsoo
On Wed, Jan 9, 2013 at 11:25 AM, Russell Jurney <[EMAIL PROTECTED]>wrote:

> Jackson is no longer needed, right? Or is it coming back in 0.11?
>
> Russell Jurney http://datasyndrome.com
>
> On Jan 9, 2013, at 10:26 AM, Cheolsoo Park <[EMAIL PROTECTED]> wrote:
>
> > Hi Milind,
> >
> > Please try this:
> >
> > REGISTER build/ivy/lib/Pig/avro-1.7.1.jar
> > REGISTER build/ivy/lib/Pig/json-simple-1.1.jar
> > REGISTER build/ivy/lib/Pig/jackson-mapper-asl-1.8.8.jar
> > REGISTER build/ivy/lib/Pig/jackson-core-asl-1.8.8.jar
> > REGISTER contrib/piggybank/java/piggybank.jar
> >
> > employee = LOAD '/home/cheolsoo/workspace/avro/emplyees' USING
> > org.apache.pig.piggybank.storage.avro.AvroStorage('multiple_schemas');
> > DESCRIBE employee;
> > DUMP employee;
> >
> > I have two Avro files in my input directory:
> >
> > $java -jar /home/cheolsoo/workspace/avro/avro-tools-1.7.1.jar tojson
> > record_employee.avro
> > {"name":"a","age":0,"dept":"b","office":"c","salary":0.0}
> >
> > $java -jar /home/cheolsoo/workspace/avro/avro-tools-1.7.1.jar tojson
> > record_employee2.avro
> > {"name":"a","age":0,"dept":"b","office":"c","salary":0}
> >
> > record_employee.avro contains a float, and record_employee2.avro contains
> > an int.
> >
> > The output looks as follows:
> >
> > ...
> > employee: {name: chararray,age: int,dept: chararray,office:
> > chararray,salary: float}
> > ...
> > (a,0,b,c,0.0)
> > (a,0,b,c,0)
> >
> > Thanks,
> > Cheolsoo
> >
> >
> >
> >
> > On Wed, Jan 9, 2013 at 6:49 AM, Milind Vaidya <[EMAIL PROTECTED]> wrote:
> >
> >> Environment:
> >>
> >> Pig version: 0.11
> >> Hadoop 0.23.6.0.1301071353
> >>
> >>
> >> Script:
> >>
> >>
> >> REGISTER /homes/immilind/HadoopLocal/Jars/avro-1.7.1.jar
> >> REGISTER /homes/immilind/HadoopLocal/Jars/jackson-all-1.8.10.jar
> >> REGISTER /homes/immilind/HadoopLocal/Jars/jackson-core-asl-1.8.10.jar
> >> REGISTER /homes/immilind/HadoopLocal/Jars/jackson-jaxrs-1.8.10.jar
> >> REGISTER /homes/immilind/HadoopLocal/Jars/jackson-mapper-asl-1.8.10.jar
> >> REGISTER /homes/immilind/HadoopLocal/Jars/jackson-xc-1.8.10.jar
> >> REGISTER /home/gs/pig/current/lib-hadoop23/piggybank.jar
> >>
> >> employee= load '/user/immilind/AvroData' using
> >> org.apache.pig.piggybank.storage.avro.AvroStorage( );
> >> dump employee;
> >>
> >>
> >> Schemas :
> >>
> >> {
> >> "type" : "record",
> >> "name" : "employee",
> >> "fields":[
> >>    {"name" : "name", "type" : "string", "default" : "NU"},
> >>    {"name" : "age", "type" : "int","default" : 0},
> >>    {"name" : "dept", "type": "string","default" : "DU"},
> >>    {"name" : "office", "type": "string","default" : "OU"},
> >>    {"name" : "salary", "type": "float","default" : 0.0}
> >> ]
> >> }
> >>
> >> {
> >> "type" : "record",
> >> "name" : "employee",
> >> "fields":[
> >>    {"name" : "name", "type" : "string", "default" : "NU"},
> >>    {"name" : "age", "type" : "int","default" : 0},
> >>    {"name" : "dept", "type": "string","default" : "DU"},
> >>    {"name" : "office", "type": "string","default" : "OU"},
> >>    {"name" : "salary", "type": "int", "default" : 0}
> >> ]
> >> }
> >>
> >>
> >> Both the schemas differ only in one field. As per the schema evolution/
> >> merging rules, I am expecting to see "int" fields loaded as "float". But
> >> instead, the job fails due to field mismatch.
> >>
> >> I am referring to :
> >>
> >> Similar thread named "Working with changing schemas (avro) in Pig"
> >>
> >>
> https://mail-archives.apache.org/mod_mbox/pig-user/201204.mbox/%[EMAIL PROTECTED]%3E
> >>
> >> JIRA:
> >> https://issues.apache.org/jira/browse/PIG-2579
> >> How to use "multiple_schema' option with "AvroStorage"  as suggested by
> >> this JIRA ?
> >>
> >> Function mergeType indicating rules for primitive types
> >>
> >>
> https://svn.apache.org/repos/asf/pig/trunk/contrib/piggybank/java/src/main/java/org/apache/pig/piggybank/storage/avro/AvroStorageUtils.java
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Russell Jurney 2013-01-09, 22:37