postgres cheatsheet
--pg indexes COOL https://www.percona.com/blog/2020/03/31/useful-queries-for-postgresql-index-maintenance/ SELECT CONCAT(n.nspname,'.', c.relname) AS table, i.relname AS index_name, pg_size_pretty(pg_relation_size(x.indrelid)) AS table_size, pg_size_pretty(pg_relation_size(x.indexrelid)) AS index_size, pg_size_pretty(pg_total_relation_size(x.indrelid)) AS total_size FROM pg_class c JOIN pg_index x ON c.oid = x.indrelid JOIN pg_class i ON i.oid = x.indexrelid LEFT JOIN pg_namespace n ON n.oid = c.relnamespace WHERE c.relkind = ANY (ARRAY['r', 't']) AND n.oid NOT IN (99, 11, 12375);
This is a collection of the most common commands I run while administering Postgres databases. The variables shown between the open and closed tags, "<" and ">", should be replaced with a name you choose. Postgres has multiple shortcut functions, starting with a forward slash, "". Any SQL command that is not a shortcut, must end with a semicolon, ";". You can use the keyboard UP and DOWN keys to scroll the history of previous commands you've run.
http://www.postgresql.org/download/linux/ubuntu/ https://help.ubuntu.com/community/PostgreSQL
sudo echo "deb http://apt.postgresql.org/pub/repos/apt/ wily-pgdg main" > \
/etc/apt/sources.list.d/pgdg.list
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
sudo apt-get update
sudo apt-get install -y postgresql-9.5 postgresql-client-9.5 postgresql-contrib-9.5
sudo su - postgres
psql
http://www.postgresql.org/docs/current/static/app-psql.html
psql
psql -U <username> -d <database> -h <hostname>
psql --username=<username> --dbname=<database> --host=<hostname>
\q
\!
(CTRL + L)
\conninfo
http://www.postgresql.org/docs/current/static/runtime-config.html
sudo nano $(locate -l 1 main/postgresql.conf)
sudo service postgresql restart
# print the last 24 lines of the debug log
sudo tail -24 $(find /var/log/postgresql -name 'postgresql-*-main.log')
SHOW SERVER_VERSION;
\conninfo
SHOW ALL;
SELECT rolname FROM pg_roles;
SELECT current_user;
\du
\l
SELECT current_database();
\dt
\df <schema>
\l
\c <database_name>
SELECT current_database();
http://www.postgresql.org/docs/current/static/sql-createdatabase.html
CREATE DATABASE <database_name> WITH OWNER <username>;
http://www.postgresql.org/docs/current/static/sql-dropdatabase.html
DROP DATABASE IF EXISTS <database_name>;
http://www.postgresql.org/docs/current/static/sql-alterdatabase.html
ALTER DATABASE <old_name> RENAME TO <new_name>;
SELECT rolname FROM pg_roles;
http://www.postgresql.org/docs/current/static/sql-createuser.html
CREATE USER <user_name> WITH PASSWORD '<password>';
http://www.postgresql.org/docs/current/static/sql-dropuser.html
DROP USER IF EXISTS <user_name>;
http://www.postgresql.org/docs/current/static/sql-alterrole.html
ALTER ROLE <user_name> WITH PASSWORD '<password>';
sudo su - postgres
psql
http://www.postgresql.org/docs/current/static/sql-grant.html
GRANT ALL PRIVILEGES ON DATABASE <db_name> TO <user_name>;
GRANT CONNECT ON DATABASE <db_name> TO <user_name>;
GRANT USAGE ON SCHEMA public TO <user_name>;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA public TO <user_name>;
GRANT SELECT, UPDATE, INSERT ON ALL TABLES IN SCHEMA public TO <user_name>;
GRANT SELECT, UPDATE, INSERT ON <table_name> TO <user_name>;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO <user_name>;
\dn
SELECT schema_name FROM information_schema.schemata;
SELECT nspname FROM pg_catalog.pg_namespace;
http://www.postgresql.org/docs/current/static/sql-createschema.html
CREATE SCHEMA IF NOT EXISTS <schema_name>;
http://www.postgresql.org/docs/current/static/sql-dropschema.html
DROP SCHEMA IF EXISTS <schema_name> CASCADE;
\dt
SELECT table_schema,table_name FROM information_schema.tables ORDER BY table_schema,table_name;
\dt *.*.
SELECT * FROM pg_catalog.pg_tables
\d <table_name>
\d+ <table_name>
SELECT column_name, data_type, character_maximum_length
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = '<table_name>';
http://www.postgresql.org/docs/current/static/sql-createtable.html
CREATE TABLE <table_name>(
<column_name> <column_type>,
<column_name> <column_type>
);
CREATE TABLE <table_name> (
<column_name> SERIAL PRIMARY KEY
);
http://www.postgresql.org/docs/current/static/sql-droptable.html
DROP TABLE IF EXISTS <table_name> CASCADE;
http://www.postgresql.org/docs/current/static/sql-altertable.html
ALTER TABLE <table_name> IF EXISTS
ADD <column_name> <data_type> [<constraints>];
ALTER TABLE <table_name> IF EXISTS
ALTER <column_name> TYPE <data_type> [<constraints>];
ALTER TABLE <table_name> IF EXISTS
DROP <column_name>;
ALTER TABLE <table_name>
ADD COLUMN <column_name> SERIAL PRIMARY KEY;
INSERT INTO <table_name>
VALUES (DEFAULT, <value1>);
INSERT INTO <table_name> (<column1_name>,<column2_name>)
VALUES ( <value1>,<value2> );
http://www.postgresql.org/docs/current/static/sql-select.html
SELECT * FROM <table_name>;
SELECT * FROM <table_name> LIMIT 1;
SELECT * FROM <table_name> WHERE <column_name> = <value>;
http://www.postgresql.org/docs/current/static/sql-insert.html
INSERT INTO <table_name> VALUES( <value_1>, <value_2> );
http://www.postgresql.org/docs/current/static/sql-update.html
UPDATE <table_name>
SET <column_1> = <value_1>, <column_2> = <value_2>
WHERE <column_1> = <value>;
http://www.postgresql.org/docs/current/static/sql-delete.html
DELETE FROM <table_name>;
DELETE FROM <table_name>
WHERE <column_name> = <value>;
http://www.postgresql.org/docs/current/static/app-psql.html
psql -U <username> -d <database> -h <host> -f <local_file>
psql --username=<username> --dbname=<database> --host=<host> --file=<local_file>
http://www.postgresql.org/docs/current/static/app-pgdump.html
pg_dump <database_name>
pg_dump <database_name>
pg_dump -a <database_name>
pg_dump --data-only <database_name>
pg_dump -s <database_name>
pg_dump --schema-only <database_name>
http://www.postgresql.org/docs/current/static/app-pgrestore.html
pg_restore -d <database_name> -a <file_pathway>
pg_restore --dbname=<database_name> --data-only <file_pathway>
pg_restore -d <database_name> -s <file_pathway>
pg_restore --dbname=<database_name> --schema-only <file_pathway>
http://www.postgresql.org/docs/current/static/sql-copy.html
\copy <table_name> TO '<file_path>' CSV
\copy <table_name>(<column_1>,<column_1>,<column_1>) TO '<file_path>' CSV
http://www.postgresql.org/docs/current/static/sql-copy.html
\copy <table_name> FROM '<file_path>' CSV
\copy <table_name>(<column_1>,<column_1>,<column_1>) FROM '<file_path>' CSV
http://www.postgresql.org/docs/current/static/using-explain.html
http://www.postgresql.org/docs/current/static/runtime-config-logging.html
http://www.tutorialspoint.com/postgresql/postgresql_constraints.htm