PostgreSQL
Contents
PostgreSQL is a free object-relational database system.
Installation
Install PostgreSQL:
emerge -a postgresql
Setup PostgresSQL:
Configuring pkg... * You can modify the paths and options passed to initdb by editing: * /etc/conf.d/postgresql-10 * * Information on options that can be passed to initdb are found at: * http://www.postgresql.org/docs/10/static/creating-cluster.html * http://www.postgresql.org/docs/10/static/app-initdb.html * * PG_INITDB_OPTS is currently set to: * --encoding=UTF8 * * Configuration files will be installed to: * /etc/postgresql-10/ * * The database cluster will be created in: * /var/lib/postgresql/10/data * * Continuing initialization in 5 seconds (Control-C to cancel) ... [ ok ] * Creating the data directory ... * Initializing the database ... The files belonging to this database system will be owned by user "postgres". This user must also own the server process. The database cluster will be initialized with locales COLLATE: en_US.utf8 CTYPE: en_US.utf8 MESSAGES: en_US.utf8 MONETARY: en_US.utf8 NUMERIC: C TIME: en_US.utf8 The default text search configuration will be set to "english". Data page checksums are disabled. fixing permissions on existing directory /var/lib/postgresql/10/data ... ok creating subdirectories ... ok selecting default max_connections ... 100 selecting default shared_buffers ... 128MB selecting dynamic shared memory implementation ... posix creating configuration files ... ok running bootstrap script ... ok performing post-bootstrap initialization ... ok syncing data to disk ... ok WARNING: enabling "trust" authentication for local connections You can change this by editing pg_hba.conf or using the option -A, or --auth-local and --auth-host, the next time you run initdb. Success. You can now start the database server using: /usr/lib64/postgresql-10/bin/pg_ctl -D /var/lib/postgresql/10/data -l logfile start * The autovacuum function, which was in contrib, has been moved to the main * PostgreSQL functions starting with 8.1, and starting with 8.4 is now enabled * by default. You can disable it in the cluster's: * /etc/postgresql-10/postgresql.conf * * The PostgreSQL server, by default, will log events to: * /var/lib/postgresql/10/data/postmaster.log * * You should use the '/etc/init.d/postgresql-10' script to run PostgreSQL * instead of 'pg_ctl'.
The output above contains the main information.
Start PostgreSQL:
postgresql-10 | * /run/postgresql: creating directory postgresql-10 | * /run/postgresql: correcting owner postgresql-10 | * Starting PostgreSQL 10 ... [ ok ]
Add the SQL server to autostart:
* service postgresql-10 added to runlevel default
Postgres user configuration
Set a password for the postgres user:
psql -U postgres
psql (10.3) Type "help" for help. postgres=# \password Enter new password: Enter it again: postgres=# \q
Database access configuration
Configure the access to the SQL server, so that local calls only be allowed, originated from the local network 192.168.0.0/24:
/etc/postgresql-10/pg_hba.conf
# TYPE DATABASE USER ADDRESS METHOD # "local" is for Unix domain socket connections only local all all password # IPv4 local connections: host all all 127.0.0.1/32 password host all all 192.168.0.0/24 password # IPv6 local connections: #host all all ::1/128 trust # Allow replication connections from localhost, by a user with the # replication privilege. #local replication all trust #host replication all 127.0.0.1/32 trust #host replication all ::1/128 trust
Specify IP addresses to be listened to by the PostgreSQL, comma-separated:
/etc/postgresql-10/postgresql.conf
#------------------------------------------------------------------------------ # CONNECTIONS AND AUTHENTICATION #------------------------------------------------------------------------------ # - Connection Settings - listen_addresses = '192.168.0.1,127.0.0.1' # what IP address(es) to listen on; # comma-separated list of addresses; # defaults to 'localhost'; use '*' for all # (change requires restart)
Note
If the server needs to be accessed from all network interfaces, set "*" instead of IPs.
Restart the database server:
postgresql-10 | * Stopping PostgreSQL 10 (this can take up to 92 seconds) ... [ ok ] postgresql-10 | * /run/postgresql: correcting mode postgresql-10 | * Starting PostgreSQL 10 ... [ ok ]
Check for operating ports:
Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:5432 0.0.0.0:* LISTEN tcp 0 0 192.168.0.1:5432 0.0.0.0:* LISTEN tcp6 0 0 :::22 :::* LISTEN udp 0 0 127.0.0.1:41006 127.0.0.1:41006 ESTABLISHED Active UNIX domain sockets (servers and established) Proto RefCnt Flags Type State I-Node Path unix 2 [ ACC ] STREAM LISTENING 281718 /run/postgresql/.s.PGSQL.5432
Exampe: create a database and a database user
Let's create a database, called dbtest and a user, called test to work with it:
psql -U postgres
Password for user postgres: psql (10.3) Type "help" for help. postgres=# create database dbtest; CREATE DATABASE postgres=# create role test with login; CREATE ROLE postgres=# \password test Enter new password: Enter it again: postgres=# grant connect, create on database dbtest to test; GRANT postgres=# \l dbtest List of databases Name | Owner | Encoding | Collate | Ctype | Access privileges --------+----------+----------+------------+------------+----------------------- dbtest | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =Tc/postgres + | | | | | postgres=CTc/postgres+ | | | | | test=Cc/postgres (1 row) postgres=# \q
The database and the database user have been created.
You can now check the user:
Password for user test: psql (10.3) Type "help" for help. test=> \q