[ https://issues.apache.org/jira/browse/PIG-813?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
George Mavromatis updated PIG-813: ---------------------------------- Component/s: (was: impl) documentation Priority: Major (was: Critical) Description: Continuation of PIG-812. See PIG-812 for more details. In order for this to be resolved in the right manner the following must added in the http://hadoop.apache.org/pig/docs/r0.2.0/piglatin.html 1) The semantics of * as explained by Olga. 2) An example of GROUP ALL Otherwise people will waste their time doing the same (documentation-caused) mistakes again. was: Pig script to count the number of rows in a studenttab10k file which contains 10k records. {code} studenttab = LOAD 'studenttab10k' AS (name:chararray, age:int,gpa:float); X2 = GROUP studenttab ALL; describe X2; Y2 = FOREACH X2 GENERATE COUNT(*); explain Y2; DUMP Y2; {code} returns the following error ================================================================ ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1066: Unable to open iterator for alias Y2 Details at logfile: /homes/viraj/pig-svn/trunk/pig_1242783700970.log ================================================================ If you look at the log file: ================================================================ Caused by: java.lang.ClassCastException at org.apache.pig.builtin.COUNT$Initial.exec(COUNT.java:76) at org.apache.pig.builtin.COUNT$Initial.exec(COUNT.java:68) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:201) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:235) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:254) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:204) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:231) at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLocalRearrange.getNext(POLocalRearrange.java:223) at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapBase.runPipeline(PigMapBase.java:245) at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapBase.map(PigMapBase.java:236) at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce$Map.map(PigMapReduce.java:88) at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:47) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:227) ================================================================ > Semantics of * and count > ------------------------ > > Key: PIG-813 > URL: https://issues.apache.org/jira/browse/PIG-813 > Project: Pig > Issue Type: Bug > Components: documentation > Affects Versions: 0.2.0 > Reporter: George Mavromatis > Fix For: 0.2.0 > > > Continuation of PIG-812. See PIG-812 for more details. > In order for this to be resolved in the right manner the following must added > in the http://hadoop.apache.org/pig/docs/r0.2.0/piglatin.html > 1) The semantics of * as explained by Olga. > 2) An example of GROUP ALL > Otherwise people will waste their time doing the same (documentation-caused) > mistakes again. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.