RE: Pg10 : Client Configuration for Parallelism ?

[<laurent.dechambe@xxxxxxxxxx>]

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) :

 

<DBEAVER>

2019-04-17 11:30:42 CEST;35895;thedbuser;thedb;00000;LOG:  00000: execute <unnamed>: SELECT COUNT(1) FROM big_table

2019-04-17 11:30:42 CEST;35895;thedbuser;thedb;00000;LOCATION:  exec_execute_message, postgres.c:1959

2019-04-17 11:31:08 CEST;35895;thedbuser;thedb;00000;LOG:  00000: duration: 25950.908 ms

2019-04-17 11:31:08 CEST;35895;thedbuser;thedb;00000;LOCATION:  exec_execute_message, postgres.c:2031

 

<BASIC JDBC>

2019-04-17 11:31:20 CEST;37257;thedbuser;thedb;00000;LOG:  00000: execute <unnamed>: SELECT COUNT(1) FROM big_table

2019-04-17 11:31:20 CEST;37257;thedbuser;thedb;00000;LOCATION:  exec_execute_message, postgres.c:1959

2019-04-17 11:31:32 CEST;37257;thedbuser;thedb;00000;LOG:  00000: duration: 11459.943 ms

2019-04-17 11:31:32 CEST;37257;thedbuser;thedb;00000;LOCATION:  exec_execute_message, postgres.c:2031

 

<PGADMIN4>

2019-04-17 11:32:56 CEST;37324;thedbuser;thedb;00000;LOG:  00000: statement: SELECT COUNT(1) FROM big_table;

2019-04-17 11:32:56 CEST;37324;thedbuser;thedb;00000;LOCATION:  exec_simple_query, postgres.c:940

2019-04-17 11:33:08 CEST;37324;thedbuser;thedb;00000;LOG:  00000: duration: 11334.677 ms

2019-04-17 11:33:08 CEST;37313;thedbuser;thedb;00000;LOG:  00000: statement: SELECT oid, format_type(oid, NULL) AS typname FROM pg_type WHERE oid IN (20) ORDER BY oid;

2019-04-17 11:33:08 CEST;37313;thedbuser;thedb;00000;LOCATION:  exec_simple_query, postgres.c:940

2019-04-17 11:33:08 CEST;37313;thedbuser;thedb;00000;LOG:  00000: duration: 0.900 ms

2019-04-17 11:33:08 CEST;37313;thedbuser;thedb;00000;LOCATION:  exec_simple_query, postgres.c:1170

 

I don’t see any difference a part from the query duration.  Note that while monitoring the server I saw that there was parallelism with JDBC program and PGAdmin4, but not with Dbeaver. And the JDBC driver is the same in both “Basic JDBC” and DBeaver.

 

Regards.

 

Laurent.

 

 

 

De : Andreas Joseph Krogh [mailto:andreas@xxxxxxxxxx]
Envoyé : mercredi 17 avril 2019 11:08
À : pgsql-performance@xxxxxxxxxxxxxxxxxxxx
Objet : Sv: Pg10 : Client Configuration for Parallelism ?

 

På onsdag 17. april 2019 kl. 08:30:28, skrev <laurent.dechambe@xxxxxxxxxx>:

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 with DBeaver (ie connected through JDBC) does not use parallelism.

SELECT current_setting('max_parallel_workers_per_gather')  gives 10 from my session.

Is there a client configuration that prevents from using parallelism ?

Thanks.

Laurent

 

Set in postgresql.conf:

 

log_statement = 'all'

 

reload settings and check the logs for what statemets are acutally issued.

 

--

Andreas Joseph Krogh

CTO / Partner - Visena AS

Mobile: +47 909 56 963

andreas@xxxxxxxxxx

www.visena.com

 

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