Re: Avg performance for int8/numeric

Bruce Momjian wrote:
> I have tested this patch but it generates regression failures.
>
> There was some code drift, so I am attaching an updated version of the
> patch, and the regression diffs. The 'four' column is an 'int4' so my
> guess is that somehow the wrong aggregate is being called.
>

Good catch - I must have neglected to run the regression test after
amending the number of array arguments for the numeric avg :-(.

Hmmm - this changing the number of array args for avg means we can't mix
transition functions for variance with final functions for avg - which
is exactly what the regression suite does with the 'newavg' aggregate.

I've 'fixed' this by amending the definition of 'newavg' to use the
transition and final function that 'avg' does. However I found myself
asking if this lost us the point of that test - so I looked back at the
older postgres versions (e.g. 7.1.3) and saw that back *then* 'newavg'
and 'avg' were defined using the same functions...so I think making the
change as indicated is ok.

I've attached a new patch with this change.

Cheers

Mark