Updates to PMP upgrade guide

content/en/docs/private-platform/pmp-quickstart.md

@@ -626,13 +626,33 @@ Re-running the installation command ensures that the installer fetches the relev
 If you have installed Private Mendix Platform before, you can upgrade it by doing the following steps:
 
 1. Ensure that your Mendix Operator version is 2.12 or above.
-2. Ensure that the number of replicas is no higher than 1. If you have manually changed the default value, make sure you revert it to 1 before attempting the upgrade.
-3. Run the command `./installer platform -n=<namespace name>`, where `-n` indicates the namespace where your Private Mendix Platform is installed.
-4. Click **Upgrade Namespace**.
+2. If you are upgrading from version 1.2.x to 2.x, make a backup of the Private Mendix Platform database by using the following command. The backup is required if you need to [roll back the upgrade]{#rollback}.
+
+    ```tex
+    pg_dump -h <DB host> -U <DB mster username> -d <database name like mendix_mxplatform_database_xxxxxxx_xxxx_xxxx_xxxx_xxxxxxxxxx> -Fc  -f <local path like /tmp/pmp_db_backup.dump>
+    ```
+
+    A `pg_dump` tool with a version equal to or higher than the Postgres database version is required.
+
+    If you are working within a pod that contains `pg_dump`, make sure to use the kubectl cp command to copy the backup to your local computer. This helps prevent the loss of the backup if the pod is deleted:
+
+    ```text
+    kubectl cp -n <psql-client-pod namespace> psql-client-pod-name:/tmp/pmp_backup.dump ./pmp_backup.dump
+    ```
+
+    To obtain the database name, use the following command:
+
+    ```text
+    kubectl get secret mxplatform-database -n <namespace for installing PMP> -o jsonpath='{.data.config}' | base64 -d
+    ```
+
+3. Ensure that the number of replicas is no higher than 1. If you have manually changed the default value, make sure you revert it to 1 before attempting the upgrade.
+4. Run the command `./installer platform -n=<namespace name>`, where `-n` indicates the namespace where your Private Mendix Platform is installed.
+5. Click **Upgrade Namespace**.
 
     {{< figure src="/attachments/private-platform/pmp-upgrade1.png" class="no-border" >}}
 
-5. Verify the following settings:
+6. Verify the following settings:
 
     * **Persist Config** - When enabled, this setting locks the Private Mendix Platform configuration, so that it can no longer be modified from the user interface.
     * **Project Management** - Recommended. Enables you to create and manage your app projects. Enables app projects and related settings across the portal. Must be enabled for CI/CD capabilities.
@@ -642,14 +662,38 @@ If you have installed Private Mendix Platform before, you can upgrade it by doin
     * **IDP** - Optional. Enable users to login using SSO by configuring your IdP integration.
     * **Webhook** - Optional. Webhooks allow to send information between platform and external systems, and can be triggered by events around Apps, Users, Groups, Marketplace and CI/CD.
 
-6. Click **Run Upgrade**.
+7. Click **Run Upgrade**.
 
     {{< figure src="/attachments/private-platform/pmp-upgrade2.png" class="no-border" >}}
 
 {{% alert color="info" %}}
 To upgrade the PCLM or Maia components, select the relevant option in the upgrade wizard. For the Svix component, you can use the Svix panel to upgrade directly.
 {{% /alert %}}
 
+### Rolling Back An Upgrade {#rollback}
+
+To restore the Private Mendix Platform database to version 1.2.x and downgrade Private Mendix Platform from version 2.x to 1.2x, perform the following steps:
+
+1. Take note of the current number of Private Mendix Platform replicas, and then scale the number down to 0.
+2. Ensure that the Private Mendix Platform pods have been terminated.
+3. For security, back up your Private Mendix Platform 2.x database (`mendix_mxplatform_database_xxxxxxx_xxxx_xxxx_xxxx_xxxxxxxxxx`).
+4. Delete the Private Mendix Platform 2.x database and create a new database with the same name by using the following commands:
+
+    1. `DROP DATABASE mendix_mxplatform_database_xxxxxxx_xxxx_xxxx_xxxx_xxxxxxxxxx"`
+    2. `CREATE DATABASE mendix_mxplatform_database_xxxxxxx_xxxx_xxxx_xxxx_xxxxxxxxxx"`
+
+5. Restore the Private Mendix Platform 1.2x database by using the following command:
+
+    ```text
+    pg_restore -U <DB master user> -h <DB host> -d <database name like mendix_mxplatform_database_xxxxxxx_xxxx_xxxx_xxxx_xxxxxxxxxx> -v /tmp/pmp_db_backup.dump
+    ```
+
+6. Connect to the `mendix_mxplatform_database_xxxxxxx_xxxx_xxxx_xxxx_xxxxxxxxxx` database, and verify that all required Private Mendix Platform tables are present and have been successfully restored.
+7. Use the Private Mendix Platform 1.2x installer to change the Private Mendix Platform image from 2.x to 1.2x
+8. Scale the number of Private Mendix Platform replicas to the previous value, ensure that at least one Private Mendix Platform pod is running.
+9. Check the Private Mendix Platform pod status and logs. 
+10. If any permissions are missing after rebuilding the database, manually reconfigure the Database Owner and the required Database, Schema, Table, and Sequence permissions.
+
 ## Running the Private Platform Configuration Wizard {#wizard}
 
 After you install Private Mendix Platform, run a one-time configuration wizard to configure the necessary settings.