async def METHOD_NAME(app):
    global db_pool
    db_pool = await asyncpg.create_pool(
        user=os.getenv('PGUSER', DBUSER),
        password=os.getenv('PGPASS', DBPSWD),
        database='hello_world',
        host=DBHOST,
        port=5432,
        min_size=MIN_POOL_SIZE,
        max_size=MAX_POOL_SIZE,        
    )