On 14/01/14 14:29, Tom Lane wrote:
[...]
> (2) the float and numeric variants should be implemented under
> nondefault names (I'm thinking FAST_SUM(), but bikeshed away). People
> who need extra speed and don't mind the slightly different results can
> alter their queries to use these variants. One reason I'm thinking
> this is that whatever we do to ameliorate the semantic issues is going
> to slow down the forward transition function --- to no benefit unless
> the aggregate is being used as a window function in a moving window.
> So I'm less than convinced that we *should* implement any of these
> designs in the default aggregates, even if we get to the point where
> we arguably *could* do it with little risk of functional differences.
> regards, tom lane
How SUM_FAST() instead, then it will more likely to be close to SUM() in
an index?
Cheers,
Gavin