How can I add row numbers for rows in PIG or HIVE?

Question

I have a problem when adding row numbers using Apache Pig. The problem is that I have a STR_ID column and I want to add a ROW_NUM column for the data in STR_ID, which is the row number of the STR_ID.

For example, here is the input:

STR_ID
------------
3D64B18BC842
BAECEFA8EFB6
346B13E4E240
6D8A9D0249B4
9FD024AA52BA

How do I get the output like:

   STR_ID    |   ROW_NUM
----------------------------
3D64B18BC842 |     1
BAECEFA8EFB6 |     2
346B13E4E240 |     3
6D8A9D0249B4 |     4
9FD024AA52BA |     5

Answers using Pig or Hive are acceptable. Thank you.

Answer 1

In Hive:

Query

select str_id,row_number() over() from tabledata;

Output

3D64B18BC842      1
BAECEFA8EFB6      2
346B13E4E240      3
6D8A9D0249B4      4
9FD024AA52BA      5

Answer 2

Facebook posted a number of hive UDFs including NumberRows. Depending on your hive version (I believe 0.8) you may need to add an attribute to the class (stateful=true).