I have re-tested the execution times with several different values of
shared_buffers in the range 256 MB - 4 GB.
It didn't solve the problem and I noticed that for values greater than 3GB
the executions halt very frequently.
I also tried to disable JIT and this further slowed it down.
But there is
Hello,
yes exactly in the previous analyses, as mentioned in the wiki, I ran
EXPLAIN (ANALYZE, BUFFERS)* query*, which took much longer to complete
(around 30 minutes) as showed in https://explain.depesz.com/s/gHrb and
https://explain.depesz.com/s/X2as .
As you said, I did the new tests with EXPLAI
I would increase shared_buffers to 1GB or more. Also, it would be very
interesting to see these queries executed with JIT off.
On Sat, Mar 06, 2021 at 10:40:00PM +0100, Francesco De Angelis wrote:
> The problem is the following: the query can take between 20 seconds and 4
> minutes to complete. Most of times, when I run the query for the first time
> after the server initialisation, it takes 20 seconds; but if I re-run it
Hello,
many thanks to all the persons who replied.
I am back with the information requested in
https://wiki.postgresql.org/wiki/Slow_Query_Questions.
Here you can find the results of the EXPLAIN commands:
1) First execution: https://explain.depesz.com/s/X2as
2) Second execution (right after the fir
You don't mention shared_buffers, which is quite low by default. Not sure
of the memory of your docker container, but it might be prudent to increase
shared_buffers to keep as much data as possible in memory rather than
needing to read from disk by a second run. To test the possibility Tom Lane
sug
Julien Rouhaud writes:
> +1, and more generally please follow
> https://wiki.postgresql.org/wiki/Slow_Query_Questions.
Yeah. FWIW, the most likely explanation for the change in behavior is
that by the time of the second execution, auto-analyze has managed to
update the table's statistics, and th
On Sun, Mar 07, 2021 at 03:51:05PM +0100, Michel SALAIS wrote:
>
> Have you tried to use EXPLAIN ANALYZE at least?
>
> It could give valuable information about why this is occurring.
+1, and more generally please follow
https://wiki.postgresql.org/wiki/Slow_Query_Questions.
Hi,
Have you tried to use EXPLAIN ANALYZE at least?
It could give valuable information about why this is occurring.
Michel SALAIS
De : Francesco De Angelis
Envoyé : samedi 6 mars 2021 22:40
À : pgsql-performance@lists.postgresql.org
Objet : Fwd: different execution time for the same
Hi all,
I would appreciate if somebody could help me understanding why the query
described below takes very different execution times to complete, almost
completely randomly.
I have two very "simple" tables, A and B:
CREATE TABLE A (
a1 varchar(10) NULL,
a2 varchar(10) NULL,
v int4 NULL
);
CREATE
10 matches
Mail list logo
