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https://issues.apache.org/jira/browse/PIG-3627?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13849808#comment-13849808
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jay vyas commented on PIG-3627:
-------------------------------
Well, so I tried many permutations of casting , and it didnt work.
In the end, I had to update my load function to pre package the originator of
the product field with chararray type.
Then, the flatten statements at the bottom of my script didnt error anymore.
I guess the schema types cant be casted in on the fly.
> Json storage : Doesn't work in cases , where other Store Functions (like
> PigStorage / AvroStorage) do work.
> ------------------------------------------------------------------------------------------------------------
>
> Key: PIG-3627
> URL: https://issues.apache.org/jira/browse/PIG-3627
> Project: Pig
> Issue Type: Bug
> Reporter: jay vyas
>
> The following query
> {code:title=Bar.java|borderStyle=solid}
> pigServer.registerQuery(
> "uniqcnt = foreach transactionsG {"+
> "sym = transactions.product ;"+
> "dsym = distinct sym ;"+
> "generate flatten(dsym.product) as product,
> COUNT(dsym) as count ;" +
> "};");
> {code}
> Results in the schema:
> {code}
> Schema : {product: NULL,count: long}
> {code}
> This schema, is storable using AvroStorage or PigStorage, but it fails if
> stored using JsonStorage:
> {code}
> Failed to parse: <line 1, column 8> Syntax error, unexpected symbol at or
> near ','
> at
> org.apache.pig.parser.QueryParserDriver.parseSchema(QueryParserDriver.java:94)
> at
> org.apache.pig.parser.QueryParserDriver.parseSchema(QueryParserDriver.java:108)
> at org.apache.pig.impl.util.Utils.parseSchema(Utils.java:208)
> at org.apache.pig.impl.util.Utils.getSchemaFromString(Utils.java:182)
> at
> org.apache.pig.builtin.JsonStorage.prepareToWrite(JsonStorage.java:140)
> at
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigOutputFormat$PigRecordWriter.<init>(PigOutputFormat.java:125)
> at
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigOutputFormat.getRecordWriter(PigOutputFormat.java:86)
> at
> org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:553)
> at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:408)
> at
> org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:216)
> {code}
> It appears that JsonStorage is thus less robust than the other storage
> formats. Can we confirm or deny if some types of data structures do/ do not
> work with JsonStorage?
> So,I suggest:
> 1) Ideally, I would think JsonStorage should support the same data that other
> Storage functions support.
> the next best thing:
> 2) Maybe a wiki page of examples that can / cannot work with JsonStorage
> and/or a better error message would be sufficient to solve this "bug".
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