I found that the following script will be converted into 3 mapreduce jobs: A = *LOAD* '/user/zjffdu/input.txt' *USING* PigStorage(); B = *GROUP* A *BY* $0; B = *FOREACH* B *GENERATE* *group*,COUNT($1); B = *ORDER* B *BY* $1; *DUMP* B; I am very interested to know How Pig compile the script to jobs, reading the source code is a way, but If there’s any document, that would be better. Does anyone know where can I find the related documents ? Or is there any JIRA item related to this ? Thank you in advance. Jeff Zhang.