Shulou(Shulou.com)06/01 Report--

-- psql function and application-- create user. Role does not have login permission create user mydbuser with encrypted password 'mydbuser';--orcreate role mydbuser with encrypted password' mydbuser';alter role mydbuser with login; by default-- create tablespace mkdir-p / pgdata/10/data/pg_tbs/tbs_mydbcreate tablespace tbs_mydb owner mydbuser location'/ pgdata/10/data/pg_tbs/tbs_mydb';-- create database create database mydb with owner=mydbuser template=template0 encoding='UTF8' tablespace=tbs_mydb -- empower grant all on database mydb to mydbuser with grant option;grant all on tablespace tbs_mydb to mydbuser;-- to view role information\ duSELECT * FROM pg_roles;-- delete role revoke all on database mydb from test;drop role test;-- connection psql mydb mydbuser-- list database information pg_database\ l color-table space list pg_tablespace\ db-- view table information pg_classcreate table test_1 (id int4,name text,create_time timestamp without time zone default clock_timestamp ()) Alter table test_1 add primary key (id);\ d test_1\ dt+ test_1insert into test_1 (id,name) select n | |'_ francs' from generate_series (1m 300000) nmittal insert into test_1 values (100001m (100001m) France') -- Index size\ di+ test_1_pkey-- get meta command psql-E mydb mydbuser-- large amount of data, copy (superuser only) has higher performance than\ copy psql mydb postgrescopy table_copy from'/ home/postgres/test_copy_in.txt';copy table_copy to'/ home/postgres/table_copy_in.txt';--csv format copy table_copy to'/ home/postgres/table_copy_in.csv' with csv header -- A unformatted output,-t displays only data psql-At-c "select oid,relname,relfilenode from pg_class limit 2" mydb mydbuser-- executes relevant script psql mydb mydbuser- f xx.sql-- to view active session select pid,usename,datname,query,client_addr from pg_stat_activity where pidpg_backend_pid () and state='active' order by query -- check the waiting event select pid,usename,datname,query,client_addr,wait_event_type,wait_event from pg_stat_activity where pidpg_backend_pid () and wait_event is not null order by wait_event_type;-- to view the number of database connections select datname,usename,client_addr,count (*) from pg_stat_activity where pidpg_backend_pid group by 1 from pg_stat_activity where pidpg_backend_pid group by 2 order by 1 desc -- Edit .psqlrc\ set active_session 'select pid,usename,datname,query,client_addr from pg_stat_activity where pidpg_backend_pid () and state=\' active\ 'order by query';-- execute: active_session-- execute the current sql\ watch [seconds] repeatedly-- view the current time select now ();-- psql view psql-- help\?

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