Diffrent results when doing sum on bulky data using proc sql with/without group by and proc means

[Parashar]

Hi,

I was doing sum for total monthly amount using group by and when I tried to validate the output of the program using simple sum in proc sql there was a difference in the sum for each month usd amount from $4 to $12, I was thinking may be due to some format ,then I applied the same formats but again difference was the same. then I tried using group by and sum it again it was matching , then for more testing I used proc means to sum the same column and I was surprised to see that now it was showing only one dollar difference.so my question is that why this difference is coming up when we use proc sql to sum a column  with group by and without group by.Is there any way to fix this issue.my data is too big approx 110gb for each month.

Thanks & Regards,

Saurabh Diwaker 

[art297]

There was another post here, recently, regarding a similar problem.  You may be trying to attain a sum that is a larger number than your machine can compute.