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Topic review (newest first)

phobucket
2012-04-23 22:54:38

Elvis is right that whatever fields are not aggregated need to be part of the group by.  If you want the other 5 columns to include data, add them to the group by section of tAggregateRow.   

If you don't want these columns, change your input format (via a tMap) to only include the 5 columns you need.

elvis
2012-04-23 19:07:03

If you think about it what else is the component to output?
Say you have the following date
Group, ValuetoSum, OtherValue
A,1,1
A,1,2
A,3,3
B,2,4
B,1,5

The first 2 columns are easy
A,5
B,3

But what value should you return for the third, it could I guess return:
A,5,1
B,3,4
i.e. the first value or
A,5,3
B,3,5
the last but either is not strictly speaking right.

If you try the same in SQL i.e.

Select Group, SUM(ValuetoSum) asValuetoSum , OtherValue
from foobar
group by Group

It'll throw an error.

emmis
2012-04-23 17:08:53

It works, but its not "beautiful" ... is there no other solution?

elvis
2012-04-23 17:05:02

If you have aggregated the multiple rows together then the component doesn't know how to handle the columns that you HAVN'T specified should be MAX'd or SUM'd.

In this circumstance I generally use first, last, max or min on the other columns.

Does this make sense?

emmis
2012-04-23 17:01:03

I have some Problems with tAggregatedRow.

tAggregatedRow itself works fine. I Make som max and sum and everythink is correct.

BUT: My datastream has 10 columns, only 4 of them are aggregated over 1 group-column. Bevor the tAggregated-Step ... tlog shows me data in all 10 columns, after the tAggregated-Step a tlog shows me only in 5 (in the aggregetd and used columns) of 10 columns data. The Rest is emty, but there. Whats wrong?

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