On Fri, 26 Jan 2024 at 17:23, Jean-Christophe Boggio
wrote:
> Let me know if I can do anything to provide you with more useful
> benchmark. The DB is still very small so it is easy to do tests.
What I was looking to find out was if there was some enable_* GUC that
you could turn off that would ma
Hello,
In case it might be useful, I made some more tests.
On my dev computer (a notebook) I installed:
PostgreSQL 15.5 (Ubuntu 15.5-1.pgdg23.10+1) on x86_64-pc-linux-gnu,
compiled by gcc (Ubuntu 13.2.0-4ubuntu3) 13.2.0, 64-bit
and
PostgreSQL 16.1 (Ubuntu 16.1-1.pgdg23.10+1) on x86_64-pc-li
David,
It would be good to narrow down which plan node is causing this. Can
you try disabling various planner enable_* GUCs before running EXPLAIN
(SUMMARY ON) with \timing on and see if you can find
which enable_* GUC causes the EXPLAIN to run more quickly? Just watch
out for variations in t
David Rowley writes:
> I do wonder now if it was a bad idea to make Memoize build the hash
> table on plan startup rather than delaying that until we fetch the
> first tuple. I see Hash Join only builds its table during executor
> run.
Ouch! If it really does that, yes it's a bad idea.
On Fri, 26 Jan 2024 at 02:31, Jean-Christophe Boggio
wrote:
> You are absolutely correct : the EXPLAIN without ANALYZE gives about the same
> results. Also, minimizing the amount of workmem in postgresql.conf changes
> drastically the timings. So that means memory allocation is eating up a lot
Hello David,
Thanks for your answer.
Le 23/01/2024 à 11:41, David Rowley a écrit :
If you're using psql, if you do \timing on, how long does EXPLAIN take
without ANALYZE? That also goes through executor startup and shutdown.
You are absolutely correct : the EXPLAIN without ANALYZE gives about
On Tue, 23 Jan 2024 at 20:45, Jean-Christophe Boggio
wrote:
> explain says actual time between 1.093→1.388 but final execution time says
> 132.880ms?!?
The 1.388 indicates the total time spent in that node starting from
just before the node was executed for the first time up until the node
retur
Hello,
No answer to my previous email, here is a simpler query with the same
problem: explain says actual time between 1.093→1.388 but final
execution time says 132.880ms?!?
Thanks for your help,
explain analyze
WITH RECURSIVE u AS (
SELECT idrealm, canseesubrealm
Hello,
This EXPLAIN ANALYZE tells me the actual time was 11.xxx ms but the
final Execution time says 493.xxx ms (this last one is true : about 1/2
second).
I would like to optimize this query but with this inconsistency, it will
be difficult. This query is really a function so I added the "p
