PostgreSQL Cookbook

Installation

Mac OS

Use homebrew from the command line:

$ brew install postgresql

Install the pyscopg library for PostgreSQL support within Python:

$ pip install psycopg2

PostgreSQL GUIs

• pgAdmin
• Postico

Troubleshooting

Compile errors installing psycopg2 involving missing -lssl libraries:

Make sure openssl is installed with brew install openssl.

Then link against brew's openssl (from within a virtual environment):

(venv) $ env LDFLAGS="-I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib" pip --no-cache install psycopg2

Windows

Search for the "PostgreSQL Windows". There is an installer available. It's pretty straightforward.

Server properties

Confirm that the server is running

$ pg_ctl status

Creating a database

Use the pgAdmin III program.

• First create a Login Role for the database. Set the database's owner to the new (or existing) login role:
  Object browser > Server Groups > [server] > Login Roles > (right click) > New Login Role
• Create the database
  Object browser > Server Groups > [server] > Databases > (right click) > New Database

Starting and stopping the server

Starting the server

$ pg_ctl -l $PGDATA/server.log start

This assumes that PGDATA has been defined in the shell profile, e.g.

export PGDATA=`/usr/local/var/postgres`

Stopping the server

$ pg_ctl stop -m fast

Restarting the server

• Run pgAdmin 4.
• Connect to the local server.
• Tools > Server Configuration > pg_hba.conf or postgresql.conf > File > Reload Server

Restarting manually

$ pg_ctl reload

I am including the information below because it's the most commonly documented method. It did not work reliably on Windows, however. It seems like not every process would be killed, and that some of them would still be attached to port 5432. The service could not be restarted after the server was stopped.

The PostgreSQL service name includes the version number.

With powershell run with Administrator privileges, navigate to the bin\ directory in the PostgreSQL installation directory.

> .\wp_ctl.exe restart -w -D "c:\ProgramData\PostgreSQL\9.4\data\"

• -w Wait for the server to stop and start.
• -D Path to data directory. The version number may be different depending on the installation.

This appears to stop the PostgreSQL service & requires the service to be manually restarted.

• Start Menu > Services (command line: services.msc)
• Check the status of the postgresql service. (Its name will end with the version number.)

Allowing remote access for pgAdmin 4

• Make sure that the PostgreSQL port (default 5432) is open on the host machine.
• Edit data\pg_hba.conf in the PosgreSQL installation directory to give the remote machine access. (Requires the PostgreSQL server to be restarted.)
• Confirm that that the PostgreSQL service is running in the Services control panel.
• ipv6 address must be added to pg_hba.conf on Windows. Append /128 to open the entire subnet of local addresses.

Querying a database from the command line

To start an interactive session:

$ psql -U [USER_NAME] [DATABASE_NAME]

Importing data

From the command line use psql:

$ psql -U [USER_NAME] [DATABASE_NAME] < [EXPORTED_DATA_FILE_NAME].sql