[ 
https://issues.apache.org/jira/browse/PIG-449?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Pradeep Kamath updated PIG-449:
-------------------------------

    Attachment: PIG-449.patch

> Schemas for bags should contain tuples all the time
> ---------------------------------------------------
>
>                 Key: PIG-449
>                 URL: https://issues.apache.org/jira/browse/PIG-449
>             Project: Pig
>          Issue Type: Bug
>    Affects Versions: types_branch
>            Reporter: Santhosh Srinivasan
>            Assignee: Pradeep Kamath
>             Fix For: types_branch
>
>         Attachments: PIG-449.patch
>
>
> The front end treats relations as operators that return bags.  When the 
> schema of a load statement is specified, the bag is associated with the 
> schema specified by the user. Ideally, the schema corresponds to the tuple 
> contained in the bag. 
> With PIG-380, the schema for bag constants are computed by the front end. The 
> schema for the bag contains the tuple which in turn contains the schema of 
> the columns. This results in errors when columns are accessed directly just 
> like the load statements.
> The front end should then treat access to the columns as a double 
> dereference, i.e., access the tuple inside the bag and then the column inside 
> the tuple.
> {code}
> grunt> a = load '/user/sms/data/student.data' using PigStorage(' ') as (name, 
> age, gpa);
> grunt> b = foreach a generate {(16, 4.0e-2, 'hello')} as b:{t:(i: int, d: 
> double, c: chararray)};
> grunt> describe b;
> b: {b: {t: (i: integer,d: double,c: chararray)}}
> grunt> c = foreach b generate b.i;
> 111064 [main] ERROR org.apache.pig.tools.grunt.GruntParser  - 
> java.io.IOException: Invalid alias: i in {t: (i: integer,d: double,c: 
> chararray)}
>         at org.apache.pig.PigServer.parseQuery(PigServer.java:293)
>         at org.apache.pig.PigServer.registerQuery(PigServer.java:258)
>         at 
> org.apache.pig.tools.grunt.GruntParser.processPig(GruntParser.java:432)
>         at 
> org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:242)
>         at 
> org.apache.pig.tools.grunt.GruntParser.parseContOnError(GruntParser.java:93)
>         at org.apache.pig.tools.grunt.Grunt.run(Grunt.java:58)
>         at org.apache.pig.Main.main(Main.java:282)
> Caused by: org.apache.pig.impl.logicalLayer.parser.ParseException: Invalid 
> alias: i in {t: (i: integer,d: double,c: chararray)}
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.AliasFieldOrSpec(QueryParser.java:5851)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.ColOrSpec(QueryParser.java:5709)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.BracketedSimpleProj(QueryParser.java:5242)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.BaseEvalSpec(QueryParser.java:4040)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.UnaryExpr(QueryParser.java:3909)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.CastExpr(QueryParser.java:3863)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.MultiplicativeExpr(QueryParser.java:3772)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.AdditiveExpr(QueryParser.java:3698)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.InfixExpr(QueryParser.java:3664)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.FlattenedGenerateItem(QueryParser.java:3590)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.FlattenedGenerateItemList(QueryParser.java:3500)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.GenerateStatement(QueryParser.java:3457)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.NestedBlock(QueryParser.java:2933)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.ForEachClause(QueryParser.java:2336)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.BaseExpr(QueryParser.java:973)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.Expr(QueryParser.java:748)
>         at 
> org.apache.pig.impl.logicalLayer.parser.QueryParser.Parse(QueryParser.java:549)
>         at 
> org.apache.pig.impl.logicalLayer.LogicalPlanBuilder.parse(LogicalPlanBuilder.java:60)
>         at org.apache.pig.PigServer.parseQuery(PigServer.java:290)
>         ... 6 more
> 111064 [main] ERROR org.apache.pig.tools.grunt.GruntParser  - Invalid alias: 
> i in {t: (i: integer,d: double,c: chararray)}
> 111064 [main] ERROR org.apache.pig.tools.grunt.GruntParser  - 
> java.io.IOException: Invalid alias: i in {t: (i: integer,d: double,c: 
> chararray)}
> grunt> c = foreach b generate b.t;
> grunt> describe c;
> c: {t: {i: integer,d: double,c: chararray}}
> {code}

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to