> 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-oracle/db-services/my-services/patching.md).

# Patching

If a higher Oracle quarterly patch version is available from Tessell, **Patch Available** appears next to the status. To view the new versions available for your DB Service, hover over **Patch Available** and then click **Patch Now**.

Patching the source is blocked when an active clone refresh schedule exists at a lower patch version. If a clone has an active refresh schedule and the clone is at a lower patch version than what you intend to patch the source to, Tessell blocks the source patch operation. To proceed with patching the source, you must either delete or pause the clone refresh schedule.

**Note**:

* Tessell highly recommends taking a snapshot of the database before patching to prevent any data loss.
* Tessell releases new Oracle PSUs to the platform within 2 weeks of release from Oracle.
* Tessell also supports publishing one-off Oracle patches to the platform.

A **Patch Database Engine Version** window pops up where you can:

1. Choose a version of the database engine available from the dropdown list.
2. Optionally, edit the number of instances to patch if the service has more than one instance. By default, all the instances are patched. The primary and HA instance update together, you cannot deselect HA instance from the primary.

   An estimated service downtime is displayed for patching.
3. Select the **Patch Database Engine Version** check box.
4. Click Start **Patch**.

The request to apply the patch is updated and following steps takes place automatically:

* Request is submitted to patch the software for DB service instances from older version to new version.
* Installs the new version of Oracle binaries.

  **Note**: For a multi-service deployment, this step is performed only for patching the first service.
* Patches the DB Service Instance(s).
* Service is ready and updates the Tessell metadata.
* For HA Services, Tessell follows Standby-First patching with rollover mode, minimizing the downtime only for the "Switchover". By default, there is one switchover during patching operation and the roles of instances are changed at the end of patching. If the customer intends to have the primary and standby instances as-is role post patching, please ask Tessell support to enable this feature flag. If this feature flag is turned on, another switchover is triggered at the end of patching.

<figure><img src="/files/oyMD5j2H3xR6x0EFAJ6S" alt=""><figcaption></figcaption></figure>


---

# 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 dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.tessell.com/tessell/tessell-for-oracle/db-services/my-services/patching.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.