# Module `Ocsipersist_config`

If you are using the PostgreSQL backend of Ocsipersist with Ocsigen Server with a configuration file, install package `ocsipersist-pgsql-config` and use the following configuration tags. All attributes of the `database` tag are optional.

One can either define a host to connect to:

```xml
<extension findlib-package="ocsipersist-pgsql-config">
  <database
     host="localhost"
     port="3000"
     user="ocsipersist"
     password="<secret>"
     size_conn_pool = "16"
  />
</extension>
```
Or a UNIX domain socket:

```xml
<extension findlib-package="ocsipersist-pgsql-config">
  <database
    unix_domain_socket_dir = "pgsql_socket"
    user="ocsipersist"
    password="<secret>"
    size_conn_pool = "16"
  />
</extension>
```