Hi
I have reported very memory expensive pattern:
CREATE OR REPLACE FUNCTION public.fx(iter integer)
RETURNS void
LANGUAGE plpgsql
AS $function$
declare
c cursor(m bigint) for select distinct i from generate_series(1, m) g(i);
t bigint;
s bigint;
begin
for i in 1..iter
loop
open c(m := i * 10000);
s := 0;
loop
fetch c into t;
exit when not found;
s := s + t;
end loop;
close c; raise notice '%=%', i, s;
end loop;
end;
$function$
;
This script takes for 100 iterations 100MB
but rewritten
CREATE OR REPLACE FUNCTION public.fx(iter integer)
RETURNS void
LANGUAGE plpgsql
AS $function$
declare
t bigint;
s bigint;
begin
for i in 1..iter
loop
s := 0;
for t in select ic from generate_series(1, i * 10000) g(ic)
loop
s := s + t;
end loop;
raise notice '%=%', i, s;
end loop;
end;
$function$
takes lot of megabytes of memory too.
Regards
Pavel
