Comments
Philipp Rautenberg wrote:
What exactly is float8_accum doing?
Susam Pal wrote:
The float8_accum is the aggregate state transition
function which maintains an internal state which changes for every
new float8 input value.
It requires a three-element array, not just two elements, because it
accumulates the sum of squares as well as the sum and count of the
inputs. This is so that it can be used for some other aggregates
besides avg.