Hello Justin and thank you for your clues.
Finally I found that putting blank to the option that limits the number of rows
to retrieve (which is normal for this kind of tool) allows PostgreSQL to
parallelize the query.
On jdbc it seems this is equivalent to write :
statement. setMaxRows(0); //
Auto explain shows that in both cases there are workers planned, but with
DBeaver they are not launched.
Here's what I get with auto_explain :
2019-04-17 14:46:09 CEST;54882;thedbuser;thedb;0;LOG: 0: duration:
0.095 ms
2019-04-17 14:46:09 CEST;54882;thedbuser;thedb;0;LOCATION:
I can see whether there is parallelism with pg_top or barely top on the server.
PID USER PR NIVIRTRESSHR S %CPU %MEM TIME+ COMMAND
38584 postgres 20 0 8863828 8.153g 8.151g R 100.0 3.2 1:23.01 postgres
10 root 20 0 0 0 0 S 0.3 0.0 8
As answered to Andreas Kretschmer all settings are identical.
I have made some other tests, even testing a basic jdbc program (open
connection, execute statement, display result, close connection)
Here are the logs (with log_error_verbosity = verbose) :
2019-04-17 11:30:42 CEST;35895;thedbuser
Thanks for the tip. I have compared all settings and they are identical.
Very strange.
-Message d'origine-
De : Andreas Kretschmer [mailto:andr...@a-kretschmer.de]
Envoyé : mercredi 17 avril 2019 10:07
À : pgsql-performance@lists.postgresql.org
Objet : Re: Pg10 : Client Configuration for
Hi,
I am working on PostgreSQL 10.5 and I have a discrepancy between clients
regarding parallelism feature.
For a simple query (say a simple SELECT COUNT(*) FROM BIG_TABLE), I can see
PostgreSQL use parallelism when the query is launched from psql or PgAdmin4.
However the same query launched w
