Even in SQL when you do select count(*) you are actually grouping, the language just hides it from you.
Each map/combiner counts the number of records it sees and sends that count to the reducer which sums the counts.
On Aug 29, 2012, at 4:41 PM, Mohit Anchlia wrote:
> Thanks! Why is grouping necessary? Is it to send it to the reducer?
> On Wed, Aug 29, 2012 at 4:03 PM, Alan Gates <[EMAIL PROTECTED]> wrote:
>> A = load 'foo';
>> B = group A all;
>> C = foreach B generate COUNT(A);
>> On Aug 29, 2012, at 3:51 PM, Mohit Anchlia wrote:
>>> How do I get count of all the rows? All the examples of COUNT use group