[](https://github.com/lcd1232/django-postgrespool2/blob/master/LICENSE)
[](https://pypi.org/project/django-postgrespool2/)
# Django-PostgresPool2
This is simple PostgreSQL connection pooling for Django. You can use it as an alternative for [PgBouncer](https://www.pgbouncer.org/).
This is a fork of the original [django-postgrespool](https://github.com/kennethreitz/django-postgrespool).
## Installation
Installing Django-PostgresPool2 is simple, with pip:
```bash
$ pip install django-postgrespool2
```
## Usage
Using Django-PostgresPool2 is simple, just set `django_postgrespool2` as your connection engine:
```python
DATABASES = {
"default": {
"ENGINE": "django_postgrespool2",
"NAME": "yourdb",
"USER": "user",
"PASSWORD": "some_password",
"HOST": "localhost",
}
}
```
If you're using the [environ](https://github.com/joke2k/django-environ) module:
```python
import environ
env = environ.Env()
DATABASES = {"default": env.db("DATABASE_URL", engine="django_postgrespool2")}
```
Everything should work as expected.
Configuration
-------------
Optionally, you can provide pool class to construct the pool (default `sqlalchemy.pool.QueuePool`) or additional options to pass to SQLAlchemy's pool creation.
List of possible values `DATABASE_POOL_CLASS` is [here](https://docs.sqlalchemy.org/en/14/core/pooling.html#api-documentation-available-pool-implementations)
```python
DATABASE_POOL_CLASS = 'sqlalchemy.pool.QueuePool'
DATABASE_POOL_ARGS = {
'max_overflow': 10,
'pool_size': 5,
'recycle': 300,
}
```
Here's a basic explanation of two of these options:
- **pool_size** – The *minimum* number of connections to maintain in the pool.
- **max_overflow** – The maximum *overflow* size of the pool. This is not the maximum size of the pool.
- **recycle** - Number of seconds between connection recycling, which means upon checkout, if this timeout is surpassed the connection will be closed and replaced with a newly opened connection.
The total number of "sleeping" connections the pool will allow is `pool_size`. The total simultaneous connections the pool will allow is `pool_size + max_overflow`.
As an example, databases in the [Heroku Postgres](https://www.heroku.com/postgres) starter tier have a maximum connection limit of 20. In that case your `pool_size` and `max_overflow`, when combined, should not exceed 20.
Check out the official [SQLAlchemy Connection Pooling](http://docs.sqlalchemy.org/en/latest/core/pooling.html#sqlalchemy.pool.QueuePool.__init__) docs to learn more about the optoins that can be defined in `DATABASE_POOL_ARGS`.
