Phoenix is backed by a SQL database. By default, if you run phoenix with no configuration, it uses SQLite. However you can also configure Phoenix to use PostgreSQL as the backend database as well.
{% hint style="info" %} Persistence is only available for 'arize-phoenix>=4.0.0' {% endhint %}
{% hint style="info" %}
Persistence for notebooks (a.k.a. launch_app) is disabled by default. To enable persistence in notebooks, set the use_temp_dir to false.
{% endhint %}
By default Phoenix uses SQLite so that it runs with no external dependancies. This SQLite instance is by default mounted in the directory specified by the PHOENIX_WORKING_DIR environment variable (default value in your home directory, e.x. ~/.phoenix/). The easiest way to make Phoenix to persist data is to back this working directory to a mounted volume. Attach the mounted volume to the phoenix pod and point PHOENIX_WORKING_DIR to that volume (e.x. /mnt/volume)\
Phoenix also can natively be backed by PostgreSQL. To make Phoenix talk to PostgreSQL instead of SQLite, you will have to set the PHOENIX_SQL_DATABASE_URL to your PostgreSQL instance.