Is there any Conditional IF like operator in Apache PIG?

Question

Actually I am writing PIG Script and want to execute some set of statements if one of the condition is satisfied.

I have set one variable and checking for some value of that variable. Suppose

if flag==0 then
  A = LOAD 'file' using PigStorage() as (f1:int, ....);
  B = ...;
  C = ....;
else 
  again some Pig Latin statements

Can I do this in PIG Script? If yes, then how can I do this?

Thanks.

Answer 1

Yes, Pig does offer an if-then-else construction, but it is not used in the way you're asking.

Pig's if-then-else is an arithmetic operator invoked with the shorthand "condition ? true_value : false_value" as part of an expression, such as:

X = FOREACH A GENERATE f2, (f2==1?1:COUNT(B));

You have to already have loaded the table A to do this. To execute control flow around entire Pig statements you'll need something like oozie, as suggested by Fakrudeen.

Answer 2

You can create a Python wrapper around your Pig script. See Embedded Pig in the docs.

Answer 3

Pig is data flow language not control flow. Only construct which comes close is PIG split, but it is very limited.

You can use oozie and its decision construct with two pig scripts.