Pig null data frame is generating data when used inside 'foreach' clause
Pardon me if I am using wrong standard pig names as I am new to it.
I have 2 dataframes in Pig (X and Y). Both having variables: j1 and j2.
I am doing below operations:
A = JOIN X by (j1) left outer, Y by (j1);
SPLIT A into B (IF Y::j1 IS NULL), C otherwise;
D = FOREACH B GENERATE X::j2;
Here, if we do DUMP B then there is no data inside it.
If we do DUMP C then data d1 appears.
But when I do DUMP D then the same data d1 appears, which is wired because B did not have any data points.
Can someone tell why it is happening?
NOTE: I have tried:
Storing B and then looking manually into part files but nothing is there in B.
I have also Stored A, then came out of session and then started the session in grunt and Loaded A and then executed last 2 lines of the code (i.e split and foreach). And when I am doing this then the code is working as expected and DUMP D is not showing any output data (which is correct).
FOUND THE SOLUTION:
It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y. Basically Jar was not able to read the csv file properly which is creating issue in join operation above.
bigdata apache-pig apache-pig-grunt
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
add a comment |
Pardon me if I am using wrong standard pig names as I am new to it.
I have 2 dataframes in Pig (X and Y). Both having variables: j1 and j2.
I am doing below operations:
A = JOIN X by (j1) left outer, Y by (j1);
SPLIT A into B (IF Y::j1 IS NULL), C otherwise;
D = FOREACH B GENERATE X::j2;
Here, if we do DUMP B then there is no data inside it.
If we do DUMP C then data d1 appears.
But when I do DUMP D then the same data d1 appears, which is wired because B did not have any data points.
Can someone tell why it is happening?
NOTE: I have tried:
Storing B and then looking manually into part files but nothing is there in B.
I have also Stored A, then came out of session and then started the session in grunt and Loaded A and then executed last 2 lines of the code (i.e split and foreach). And when I am doing this then the code is working as expected and DUMP D is not showing any output data (which is correct).
FOUND THE SOLUTION:
It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y. Basically Jar was not able to read the csv file properly which is creating issue in join operation above.
bigdata apache-pig apache-pig-grunt
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
Are you sure that your second statement runs without error? You need to tell Pig whichj1you are referring to:X::j1orY::j1. The decision might result inBhaving or not having data due to the left outer join. While addingDUMPstatements are you sure that none of your other statements are changing?
– Rajeev Atmakuri
Nov 9 '18 at 8:00
Hi, apologies for the typo. I have added Y::j1 in the code. And now the code is exactly same with no changes at all. So no other statements are changing while dumping.
– Bhuvi007
Nov 9 '18 at 8:28
Can you share a sample input, expected output and actual output? It's not clear to me what "d1" is referring to (since your script does not have any "d1".)
– Koji
Nov 21 '18 at 18:01
Hi, the issue is resolved. It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y.
– Bhuvi007
Nov 22 '18 at 6:25
add a comment |
Pardon me if I am using wrong standard pig names as I am new to it.
I have 2 dataframes in Pig (X and Y). Both having variables: j1 and j2.
I am doing below operations:
A = JOIN X by (j1) left outer, Y by (j1);
SPLIT A into B (IF Y::j1 IS NULL), C otherwise;
D = FOREACH B GENERATE X::j2;
Here, if we do DUMP B then there is no data inside it.
If we do DUMP C then data d1 appears.
But when I do DUMP D then the same data d1 appears, which is wired because B did not have any data points.
Can someone tell why it is happening?
NOTE: I have tried:
Storing B and then looking manually into part files but nothing is there in B.
I have also Stored A, then came out of session and then started the session in grunt and Loaded A and then executed last 2 lines of the code (i.e split and foreach). And when I am doing this then the code is working as expected and DUMP D is not showing any output data (which is correct).
FOUND THE SOLUTION:
It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y. Basically Jar was not able to read the csv file properly which is creating issue in join operation above.
bigdata apache-pig apache-pig-grunt
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
Pardon me if I am using wrong standard pig names as I am new to it.
I have 2 dataframes in Pig (X and Y). Both having variables: j1 and j2.
I am doing below operations:
A = JOIN X by (j1) left outer, Y by (j1);
SPLIT A into B (IF Y::j1 IS NULL), C otherwise;
D = FOREACH B GENERATE X::j2;
Here, if we do DUMP B then there is no data inside it.
If we do DUMP C then data d1 appears.
But when I do DUMP D then the same data d1 appears, which is wired because B did not have any data points.
Can someone tell why it is happening?
NOTE: I have tried:
Storing B and then looking manually into part files but nothing is there in B.
I have also Stored A, then came out of session and then started the session in grunt and Loaded A and then executed last 2 lines of the code (i.e split and foreach). And when I am doing this then the code is working as expected and DUMP D is not showing any output data (which is correct).
FOUND THE SOLUTION:
It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y. Basically Jar was not able to read the csv file properly which is creating issue in join operation above.
bigdata apache-pig apache-pig-grunt
bigdata apache-pig apache-pig-grunt
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
edited Nov 22 '18 at 6:27
Bhuvi007
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
asked Nov 9 '18 at 5:32
Bhuvi007Bhuvi007
176
176
Are you sure that your second statement runs without error? You need to tell Pig whichj1you are referring to:X::j1orY::j1. The decision might result inBhaving or not having data due to the left outer join. While addingDUMPstatements are you sure that none of your other statements are changing?
– Rajeev Atmakuri
Nov 9 '18 at 8:00
Hi, apologies for the typo. I have added Y::j1 in the code. And now the code is exactly same with no changes at all. So no other statements are changing while dumping.
– Bhuvi007
Nov 9 '18 at 8:28
Can you share a sample input, expected output and actual output? It's not clear to me what "d1" is referring to (since your script does not have any "d1".)
– Koji
Nov 21 '18 at 18:01
Hi, the issue is resolved. It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y.
– Bhuvi007
Nov 22 '18 at 6:25
add a comment |
Are you sure that your second statement runs without error? You need to tell Pig whichj1you are referring to:X::j1orY::j1. The decision might result inBhaving or not having data due to the left outer join. While addingDUMPstatements are you sure that none of your other statements are changing?
– Rajeev Atmakuri
Nov 9 '18 at 8:00
Hi, apologies for the typo. I have added Y::j1 in the code. And now the code is exactly same with no changes at all. So no other statements are changing while dumping.
– Bhuvi007
Nov 9 '18 at 8:28
Can you share a sample input, expected output and actual output? It's not clear to me what "d1" is referring to (since your script does not have any "d1".)
– Koji
Nov 21 '18 at 18:01
Hi, the issue is resolved. It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y.
– Bhuvi007
Nov 22 '18 at 6:25
Are you sure that your second statement runs without error? You need to tell Pig which
j1 you are referring to: X::j1 or Y::j1. The decision might result in B having or not having data due to the left outer join. While adding DUMP statements are you sure that none of your other statements are changing?– Rajeev Atmakuri
Nov 9 '18 at 8:00
Are you sure that your second statement runs without error? You need to tell Pig which
j1 you are referring to: X::j1 or Y::j1. The decision might result in B having or not having data due to the left outer join. While adding DUMP statements are you sure that none of your other statements are changing?– Rajeev Atmakuri
Nov 9 '18 at 8:00
Hi, apologies for the typo. I have added Y::j1 in the code. And now the code is exactly same with no changes at all. So no other statements are changing while dumping.
– Bhuvi007
Nov 9 '18 at 8:28
Hi, apologies for the typo. I have added Y::j1 in the code. And now the code is exactly same with no changes at all. So no other statements are changing while dumping.
– Bhuvi007
Nov 9 '18 at 8:28
Can you share a sample input, expected output and actual output? It's not clear to me what "d1" is referring to (since your script does not have any "d1".)
– Koji
Nov 21 '18 at 18:01
Can you share a sample input, expected output and actual output? It's not clear to me what "d1" is referring to (since your script does not have any "d1".)
– Koji
Nov 21 '18 at 18:01
Hi, the issue is resolved. It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y.
– Bhuvi007
Nov 22 '18 at 6:25
Hi, the issue is resolved. It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y.
– Bhuvi007
Nov 22 '18 at 6:25
add a comment |
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Are you sure that your second statement runs without error? You need to tell Pig which
j1you are referring to:X::j1orY::j1. The decision might result inBhaving or not having data due to the left outer join. While addingDUMPstatements are you sure that none of your other statements are changing?– Rajeev Atmakuri
Nov 9 '18 at 8:00
Hi, apologies for the typo. I have added Y::j1 in the code. And now the code is exactly same with no changes at all. So no other statements are changing while dumping.
– Bhuvi007
Nov 9 '18 at 8:28
Can you share a sample input, expected output and actual output? It's not clear to me what "d1" is referring to (since your script does not have any "d1".)
– Koji
Nov 21 '18 at 18:01
Hi, the issue is resolved. It was not actually the Pig issue. It was Jar issue which I was using to read data and hence creating data frames X and Y.
– Bhuvi007
Nov 22 '18 at 6:25