pg_lsclusters
Ver Cluster Port Status Owner Data directory Log file
9.2 main 5431 online postgres /var/lib/postgresql/9.2/main /var/log/postgresql/postgresql-9.2-main.log
9.3 main 5432 online postgres /var/lib/postgresql/9.3/main /var/log/postgresql/postgresql-9.3-main.log
9.4 main 5433 online postgres /var/lib/postgresql/9.4/main /var/log/postgresql/postgresql-9.4-main.log
9.5 main 5434 online postgres /var/lib/postgresql/9.5/main /var/log/postgresql/postgresql-9.5-main.log
9.6 main 5435 online postgres /var/lib/postgresql/9.6/main /var/log/postgresql/postgresql-9.6-main.log
10 main 5436 online postgres /var/lib/postgresql/10/main /var/log/postgresql/postgresql-10-main.log
-- choix de travailler avec la version 10, port 5436
select version();
version
-----------------------------------------------------------------------------------------------------------------
PostgreSQL 10rc1 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609, 64-bit
show max_connections;
max_connections
-----------------
2000
(1 ligne)
-- preparation environnement
create table t1(c1 int);
CREATE TABLE
insert into t1 values(1),(2),(3);
INSERT 0 3
-- session A
select pg_backend_pid();
pg_backend_pid
----------------
6584
(1 ligne)
start transaction;
START TRANSACTION
update t1 set c1 = 11 where c1 = 1;
UPDATE 1
update t1 set c1 = 22 where c1 = 2;
UPDATE 1
-- session B
select pg_backend_pid();
pg_backend_pid
----------------
6598
(1 ligne)
start transaction;
START TRANSACTION
update t1 set c1 = 33 where c1 = 3;
UPDATE 1
update t1 set c1 = 222 where c1 = 2;
-- EN ATTENTE !!!!
-- 500 * session C -- 10 appels à une ligne en bash effectuant 50 connexions
for i in {1..50}; do psql -p 5436 -c "update t1 set c1 = 333 where c1 = 3" & done
...
for i in {1..50}; do psql -p 5436 -c "update t1 set c1 = 333 where c1 = 3" & done
-- EN ATTENTE !!!