Simple Queues With Plain Postgres

This is work in progres.

Idea

Provide easy to use and fast enough queues on plain Postgres.

The whole solution is based on two builtin Postgres features:

• asynchronous notifications via LISTEN/NOTIFY
• SKIP LOCKED

For convinience there are a couple of small PL/PGSQL functions like create_queue() or delete_queue(). See functions.sql for details.

Using A Queue

Create queue:

SELECT create_queue('orderdata');

Writing to the queue:

INSERT INTO queue_orderdata VALUES ('this is the payload');

Reading (Python example):

conn = psycopg2.connect("dbname=postgres user=samba")
conn.autocommit = True
cursor = conn.cursor()

def main():
    while True:
        entry = read_queue("orderdata", cursor)
        print("Received: " + entry)

Delete queue:

SELECT delete_queue('orderdata');

Contribute

See Makefile for how to:

• install the functions in the database
• create a Python virtual env for testing

Currently Done

• simple FIFO queue
• log which keeps data