> 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/database-engines/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 service status.

***

## How do I know when a patch is available?

**Patch Available** appears next to the service status. Hover over it and click **Patch Now** to view the available versions.

***

## How do I apply a PostgreSQL patch?

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

1. Hover over **Patch Available** next to the service status → click **Patch Now**.
2. In the **Patch Database Engine Version** window:
   1. Choose a version of the database engine from the dropdown list.
   2. (Optional) 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** checkbox.
   4. Click **Start Patch**.

Tessell then performs the following steps automatically:

1. Submits the request to patch the software for database service instances.
2. Installs the new version of PostgreSQL binaries.
3. Patches the database service instance(s).
4. Sets the service status to **Ready** and updates Tessell metadata.

***

## How does patching work for HA services?

For HA services, Tessell follows **Standby-First patching with rollover mode** to minimize downtime.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.tessell.com/tessell/database-engines/tessell-for-postgresql/db-services/readme-postgresql/patching-postgresql.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.