Justin,
I'm really not a expert in this area, on how to code this, or functions in
PostgreSQL. All I could offer is some ideas which you might try. Sometimes
this is all it takes. Perhaps someone else will respond that might be more
helpful. With that said I have read in the documentation the use of other
languages and if you are looking for a higher performance, that is the
way I would said its going to come about perhaps.
danap.
DMP you did give me an idea on changing how to call the append array
sfunc looks like this
create or replace function wcost_average_sf (numeric[], numeric,
numeric)
returns numeric[] as
$Body$
begin
return array_append(array_append($1, $2), $3);
end;
$Body$
LANGUAGE 'plpgsql' VOLATILE;
this yanked out 140,000 ms on the run time, a big improvement but
no where i want it to be.
are there speed improvements in the other languages TCL
dmp wrote:
Array appends are usually a performance hit, as you said. I'm not
sure though with
PostgreSQL. Why not try it with two arrays and see what happens. At
least you would
reducing the single array and the eliminating the append.
danap.
I got the aggregate function for weighted average done. I finely
left alone for more than 10 minutes to actual get it written. It
takes 2 value input Weight and the Value. it will sum the weighted
entries to create the constant then does the normal formula, but
does not percentage number but averaged number. A simple change on
the return line it can do percentages.
I did a couple of things a little odd . instead of doing a multi
dimensional array i did a one dimensional array where the 1st row is
Weight and the 2nd row is Value. This made the loop through the
array look stupid.
I tested it across 50,000 records with a group by it took 3.3
seconds to run.
without the group by clause performance is terrible taking several
minutes just to do the sfunc part. 371,563ms
The Array seems to have performance hit any advice? It could be
the way i'm appending to the Array which has a performance hit as
the array gets bigger and bigger ?
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