> For the complete documentation index, see [llms.txt](https://docs.tessell.com/tessell/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tessell.com/tessell/tessell-for-postgresql/db-services/readme-postgresql/patching-postgresql.md).

# Patching

If a higher patch version is available from Tessell, **Patch Available** appears next to the status. Hover over **Patch Available** and click **Patch Now** to view the available versions.

> **Note**: Tessell highly recommends taking a snapshot of the database before patching to prevent data loss.

A **Patch Database Engine Version** window appears where you can:

1. Choose a version of the database engine from the dropdown list.
2. Optionally, edit the number of instances to patch if the service has more than one instance. By default, all instances are patched.\
   An estimated service downtime is displayed for patching.
3. Select the **Patch Database Engine Version** check box.
4. Click **Start Patch**.

The following steps are performed automatically:

* Request is submitted to patch the software for database service instances.
* New version of PostgreSQL binaries is installed.
* Database service instance(s) are patched.
* Service returns to Ready status and Tessell metadata is updated.
* For HA services, Tessell follows Standby-First patching with rollover mode to minimize downtime.


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