# Limitations

* **Connection Limits:** The value for [<mark style="color:blue;">max\_connections</mark>](https://www.postgresql.org/docs/current/runtime-config-connection.html) is calculated based on RAM size.

| **RAM Size** | **max\_connections** |
| :----------: | -------------------: |
|      4GB     |                  384 |
|      5GB     |                  512 |
|      6GB     |                  640 |
|      7GB     |                  768 |
|      8GB     |                  896 |
|     > 8GB    |                 1000 |

The superuser needs to maintain the state and integrity of the database, which is why the platform reserves 11 connections for internal use: connections for superusers, see [<mark style="color:blue;">superuser\_reserved\_connections</mark>](https://www.postgresql.org/docs/current/runtime-config-connection.html) for replication.

{% hint style="info" %}
**Note:** The total upper limit for **CPU cores**, **RAM**, and **Storage** depends on your contract limits.
{% endhint %}

* **Backups:** Storing cluster backups in an IONOS S3 Object Storage is limited to the last 7 days.
* **IP Ranges:** The following IP ranges cannot be used with our PostgreSQL services:
  * `10.208.0.0/12`
  * `10.233.0.0/18`
  * `192.168.230.0/24`
  * `10.233.64.0/18`

{% hint style="info" %}
**Note:** Enable `PgBouncer` for connection pooling when your application creates many short-lived connections or when client connections may exceed PostgreSQL’s `max_connections`. `PgBouncer` keeps backend processes low, improves latency, and protects the database from connection overload. For activation instructions, see [<mark style="color:blue;">Activating the connection pooler (PgBouncer)</mark>](https://docs.ionos.com/sections-test/guides/databases/postgresql/api/v1-api/modify-cluster-attributes/activate-a-postgresql-connection-pooler).
{% endhint %}