Postgres commands list

postgres-commands

Start Postgres without background service:
pg_ctl -D /usr/local/var/postgres start

Login to postgresql:
psql -d mydb -U myuser -W
psql -h myhost -d mydb -U myuser -W
psql -U myuser -h myhost "dbname=mydb sslmode=require" # ssl connection

Default Admin Login:
sudo -u postgres psql -U postgres
sudo -u postgres psql

List databases on postgresql server:
psql -l [-U myuser] [-W]

Turn off line pager pagination in psql:
\pset pager

Determine system tables:
select * from pg_tables where tableowner = 'postgres';

List databases from within a pg shell:
\l

List databases from UNIX command prompt:
psql -U postgres -l

Describe a table:
\d tablename

Quit psql:
\q

Switch postgres database within admin login shell:
\connect databasename

Reset a user password as admin: 
alter user usertochange with password 'new_passwd'; 

Show all tables:
\dt

List all Schemas: 
\dn

List all users:
\du

Load data into posgresql:
psql -W -U username -H hostname < file.sql 

Dump (Backup) Data into file:
pg_dump -W -U username -h hostname database_name > file.sql 

Increment a sequence:
SELECT nextval('my_id_seq');

Create new user:
CREATE USER jjasinski WITH PASSWORD 'myPassword';
# or
sudo -u postgres createuser jjasinski -W

Change user password: 
ALTER USER Postgres WITH PASSWORD 'mypass';

Grant user createdb privilege: 
ALTER USER myuser WITH createdb; 

Create a superuser user:
create user mysuper with password '1234' SUPERUSER
# or even better
create user mysuper with password '1234' SUPERUSER CREATEDB CREATEROLE INHERIT LOGIN REPLICATION;
# or
sudo -u postgres createuser jjasinski -W -s

Upgrade an existing user to superuser: 
alter user mysuper with superuser;
# or even better
alter user mysuper with SUPERUSER CREATEDB CREATEROLE INHERIT LOGIN REPLICATION

Show Database Version:
SELECT version();

Change Database Owner:
alter database database_name owner to new_owner;

Copy a database: 
CREATE DATABASE newdb WITH TEMPLATE originaldb;
http://www.commandprompt.com/ppbook/x14316

View Database Connections:
SELECT * FROM pg_stat_activity;

View show data directory (works on 9.1+; not on 7.x):
show data_directory;

Show run-time parameters:
show all;
select * from pg_settings;

Show the block size setting:
# show block_size;
 block_size
------------
 8192
(1 row)

Show stored procedure source:
SELECT prosrc FROM pg_proc WHERE proname = 'procname'

Grant examples:
# readonly to all tables for myuser
grant select on all tables in schema public to myuser;
# all privileges on table1 and table2 to myuser
grant all privileges on table1, table2, table3 to myuser;

Restore Postgres .dump file:
pg_restore --verbose --clean --no-acl --no-owner -h localhost -U myuser -d mydb latest.dump
source

Find all active sessions and kill them (i.e. for when needing to drop or rename db)
Source: http://stackoverflow.com/questions/5408156/how-to-drop-a-postgresql-database-if-there-are-active-connections-to-it

# Postgres 9.2 and above
SELECT pg_terminate_backend(pg_stat_activity.pid) 
FROM pg_stat_activity 
WHERE pg_stat_activity.datname = 'TARGET_DB' 
 AND pid <> pg_backend_pid();

# Postgres 9.1 and below
SELECT pg_terminate_backend(pg_stat_activity.procpid) 
FROM pg_stat_activity 
WHERE pg_stat_activity.datname = 'TARGET_DB' 
AND procpid <> pg_backend_pid();


Re-read postgres config without dropping connections (i.e. if postgres.conf or pg_hba.conf changes)
Source: http://www.heatware.net/databases/postgresql-reload-config-without-restarting/

/usr/bin/pg_ctl reload
or
SELECT pg_reload_conf();

Per user query logging (logs to to postgres logs):
alter role myuser set log_statement = 'all'; 

Force disconnect clients from DB ( to be able to DROP active DB)
- First get process id: SELECT pg_backend_pid();
- SELECT pg_terminate_backend(procpid) FROM pg_stat_activity WHERE datname = 'mydbname';