Alexander Pyhalov писал(а) 2025-01-29 17:35: > Tom Lane писал(а) 2025-01-17 21:27: >> Alexander Pyhalov <a.pyhalov@postgrespro.ru> writes: >>> I've rebased patch on master. Tests pass here. >> >> The cfbot still doesn't like it; my guess is that you built without >> --with-libxml and so didn't notice the effects on xml.out. > > Hi. Thank you for review. > > I've updated patch.
Sorry, missed one local patch to fix memory bloat during replaning. Also fixed a compiler warning.
Did you do some performance checks?
I tried some worst case
CREATE OR REPLACE FUNCTION fx(int)
RETURNS int AS $$
SELECT $1 + $1
$$ LANGUAGE SQL IMMUTABLE;
CREATE OR REPLACE FUNCTION fx2(int)
RETURNS int AS $$
SELECT $1 * 2
$$ LANGUAGE SQL IMMUTABLE;
do $$ begin for i in 1..1000000 loop perform fx(i); -- or fx2 end loop; end; $$; DO
The patched version reduces the difference between execution fx and fx2, but patched version is about 10% slower than unpatched.
The overhead of plan cache looks significant for simple cases (and a lot of SQL functions are very simple).
Regards
Pavel
-- Best regards, Alexander Pyhalov, Postgres Professional
