# Upgrading PostgreSQL extensions in RDS for PostgreSQL databases
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A PostgreSQL engine upgrade doesn't upgrade most PostgreSQL extensions. To update an extension after a version upgrade, use the `ALTER EXTENSION UPDATE` command. 

**Note**  
For information about updating the PostGIS extension, see [Managing spatial data with the PostGIS extension](Appendix.PostgreSQL.CommonDBATasks.PostGIS.md) ([Step 6: Upgrade the PostGIS extension](Appendix.PostgreSQL.CommonDBATasks.PostGIS.md#Appendix.PostgreSQL.CommonDBATasks.PostGIS.Update)).  
To update the `pg_repack` extension, drop the extension and then create the new version in the upgraded database. For more information, see [pg\$1repack installation](https://reorg.github.io/pg_repack/) in the `pg_repack` documentation.

To upgrade an extension, use the following command. 

```
ALTER EXTENSION extension_name UPDATE TO 'new_version';
```

For the list of supported versions of PostgreSQL extensions, see [Supported PostgreSQL extension versions](PostgreSQL.Concepts.General.FeatureSupport.Extensions.md).

To list your currently installed extensions, use the PostgreSQL [pg\$1extension](https://www.postgresql.org/docs/current/catalog-pg-extension.html) catalog in the following command.

```
SELECT * FROM pg_extension;
```

To view a list of the specific extension versions that are available for your installation, use the PostgreSQL [ pg\$1available\$1extension\$1versions](https://www.postgresql.org/docs/current/view-pg-available-extension-versions.html) view in the following command.

```
SELECT * FROM pg_available_extension_versions;
```