Quick Ref.
Compatibility
SUM(f)
Engine OK Alternative
ingres yes
oracle yes
postgres yes
sqlserver yes

SUM

SUM adds a whole column of values.

SUM is an aggregate function it is normally used with GROUP BY. 

  SELECT region, SUM(population)
    FROM bbc
   GROUP BY region
With a GROUP BY region statement each region shows up just once. The SUM column gives the total for each region.

Results
See also: