illustrate 运算符为你提供了一系列语句的逐步执行。
下面给出了illustrate运算符的语法。
grunt> illustrate Relation_name;
假设在HDFS中有一个包含以下内容的文件 student_data.txt 。
001,Rajiv,Reddy,9848022337,Hyderabad
002,siddarth,Battacharya,9848022338,Kolkata
003,Rajesh,Khanna,9848022339,Delhi
004,Preethi,Agarwal,9848022330,Pune
005,Trupthi,Mohanthy,9848022336,Bhuwaneshwar
006,Archana,Mishra,9848022335,Chennai.
使用LOAD运算符将它读入关系 student ，如下所示。
grunt> student = LOAD 'hdfs://localhost:9000/pig_data/student_data.txt' USING PigStorage(',')
as ( id:int, firstname:chararray, lastname:chararray, phone:chararray, city:chararray ); 现在，让我们说明如下所示的名为student的关系。
grunt> illustrate student;
在执行上面的语句时，将获得以下输出。
grunt> illustrate student;
INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapOnly$M ap - Aliases
being processed per job phase (AliasName[line,offset]): M: student[1,10] C: R:
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|student | id:int | firstname:chararray | lastname:chararray | phone:chararray | city:chararray |
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| | 002 | siddarth | Battacharya | 9848022338 | Kolkata |
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