Marco Kienzle <m.kienzle@marlab.ac.uk> writes:
> herring=3D# select sum(agenum) from age where weightmeanage>0 and lengthcel=
> l=3D160;
> sum=20
> -----
> 77
> (1 row)
> select INTO TABLE temp1 inst, year, month, lengthcell, sex, age, agenum, w=
> eightmeanage from age where weightmeanage>0 and lengthcell=3D160 group by i=
> nst, year, month, lengthcell, sex,age,agenum, weightmeanage;
> herring=3D# select sum(agenum) from temp1;
> sum=20
> -----
> 73
> (1 row)
Why would you expect these to give the same result? The "group by"
effectively eliminates duplicate rows, thus removing some contributions
to the sum.
regards, tom lane
