Hello
it isn't surprise. PL/pgSQL hasn't own arithmetic unit. All
expressions are transformed to simple SELECTs.
Probably you can find a tasks, where Perl should be 10, 100, 1000x
faster than PL/pgSQL - array sort, array creation, ..
On second hand, PL/pgSQL is very fast with embeded SQL.
So if you need to calculate a numeric expensive task, then you need to
use Perl, maybe Python or C. If you need to join a embedded SQL, then
PL/pgSQL is good tool.
Regards
Pavel Stehule
p.s. Once I had to solve very slow statistical analysis. 99% of time
needed a bublesort implemented in PL/pgSQL. When I replaced it by
buildin quicksort in SQL language, the problem was solved.
2011/2/8 pasman pasmański <pasman.p@gmail.com>:
> Hi.
> I do small test of plsql and perl.Result is that perl may be
> 2xfaster in simple loops.
>
>
> CREATE OR REPLACE FUNCTION _.test1() RETURNS void AS
> $BODY$
> declare i integer; j bigint := 0;
> begin
> for i in 1..1000000 loop j:=j+i; end loop;
> end;
> $BODY$ LANGUAGE plpgsql VOLATILE COST 100;
>
> "Result (cost=0.00..0.26 rows=1 width=0) (actual
> time=1382.851..1382.853 rows=1 loops=1)"
> "Total runtime: 1383.167 ms"
>
>
> CREATE OR REPLACE FUNCTION _.test2() RETURNS void AS
> $BODY$
> $j=0;
> for($i=0;$i<1000000;$i++) {
> $j = $j + $i;
> }
> $BODY$ LANGUAGE plperlu VOLATILE COST 100;
>
> "Result (cost=0.00..0.26 rows=1 width=0) (actual
> time=584.272..584.275 rows=1 loops=1)"
> "Total runtime: 584.355 ms"
>
>
> ------------
> pasman
>
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