I am glad that you got this in a replicatable form! I have seen this error as well (where the output is just the last value repeated instead of the multiples that you want), but wasn't able to give a concrete example.
2011/2/16 James Kebinger <[email protected]> > Hello all, I've been scratching my head over a problem with a pig script > I'm > having, and hoping another set of eyeballs will help. I'm using pig 0.8, in > local mode > > Here's my simplified use case: > > I have a log file with events on pages, and the id of the event can be a > users login or a users numeric id: > > 2010-05-14,james > 2010-05-15,123 > 2010-05-15,23 > 2010-05-15,456 > 2010-05-15,notjames > > So i want to join a set of users on either the login or user id. > > Here's my users: > > 123,james,11 > 234,notjames,11 > 456,someoneelse,11 > > > So I thought I would be clever and load the user list, union it with itself > to generate a relation where each user is represented twice, once by login, > once by id: > > logins = FOREACH users GENERATE LOWER(login) as matching_id, user_id as > actual_user_id; > user_ids = FOREACH users GENERATE user_id as matching_id, user_id as > actual_user_id; > user_id_or_login_lookup = UNION logins, user_ids; > > > > user_id_or_login_lookup: {matching_id: chararray,actual_user_id: chararray} > (123,123) > (234,234) > (456,456) > (james,123) > (notjames,234) > (someoneelse,456) > > Then join on that, by the first column, and project that away, leaving just > the event info and the numeric id. > > views_with_id = JOIN profile_views by viewed_user_id, > user_id_or_login_lookup by matching_id; > > That is not working however. My joined relation looks like this (which is > what I expect) > > views_with_id: {profile_views::date: > chararray,profile_views::viewed_user_id: > chararray,user_id_or_login_lookup::matching_id: > chararray,user_id_or_login_lookup::actual_user_id: chararray} > > (2010-05-15,123,123,123) > (2010-05-15,456,456,456) > (2010-05-14,james,james,123) > (2010-05-15,notjames,notjames,234) > > But when I project as follows: views_with_id_projected = FOREACH > views_with_id GENERATE date, viewed_user_id, > user_id_or_login_lookup::actual_user_id; > > The result is not what I expect > > (2010-05-15,123,123) > (2010-05-15,456,456) > (2010-05-14,james,james) > (2010-05-15,notjames,notjames) > > To be clear, I expect > > (2010-05-15,123,123) > (2010-05-15,456,456) > (2010-05-14,james,123) > (2010-05-15,notjames,456) > > > Can anyone give me a push in the right direction? > > Thanks, James > > Here's my full pig script: > > users = LOAD 'patients-test.txt' USING PigStorage(',') AS > (user_id:chararray, login:chararray, disease_id: chararray); > profile_views = LOAD 'patient-views-test.txt' USING PigStorage(',') > AS(date: > chararray, viewed_user_id:chararray); > > dump users; > dump profile_views; > > -- build a relation so that users are present to join by login or user_id > logins = FOREACH users GENERATE LOWER(login) as matching_id, user_id as > actual_user_id; > user_ids = FOREACH users GENERATE user_id as matching_id, user_id as > actual_user_id; > user_id_or_login_lookup = UNION logins, user_ids; > > dump user_id_or_login_lookup; > describe user_id_or_login_lookup; > > views_with_id = JOIN profile_views by viewed_user_id, > user_id_or_login_lookup by matching_id; > > describe views_with_id; > --STORE views_with_id into 'ep-views.txt'; > > dump views_with_id; > > views_with_id_projected = FOREACH views_with_id GENERATE date, > viewed_user_id, user_id_or_login_lookup::actual_user_id; > > > dump views_with_id_projected; >
