---
title: "Add extensions"
description: "Add PostgreSQL extensions such as pgvector to a TIR DBaaS database, when you create it or later from Edit, and see which extensions are on offer."
content_type: "how-to"
product: "tir-dbaas"
platform: "TIR"
url: "/tir/tir-dbaas/how-to/add-extensions/"
topic: ["configure"]
---

# Add extensions

<!-- cspell:ignore pgvector pgcrypto citext ltree unaccent plpgsql -->

Extensions add features to PostgreSQL, such as vector similarity search with pgvector. Choose them
when you create a database, and add more later from **Edit**. The database keeps running while you add
any of the extensions on offer.

## Before you begin

- A TIR project in Chennai, where DBaaS is offered.
- The DBaaS create permission to choose extensions on a new database, or the update permission to
  add them to an existing one. See [TIR Access Control](/tir/tir-iam/).
- A database in the **Running** state, if you are adding extensions to an existing one.

## Extensions you can add

| Extension          | What it adds                                      |
| ------------------ | ------------------------------------------------- |
| pg_stat_statements | Statistics on how queries run                     |
| vector             | pgvector, vector similarity search for embeddings |
| pg_trgm            | Trigram matching for fuzzy text search            |
| uuid-ossp          | Functions that generate UUIDs                     |
| pgcrypto           | Cryptographic functions                           |
| hstore             | Key and value pairs in a single column            |
| citext             | A case-insensitive text type                      |
| btree_gin          | GIN index support for common types                |
| btree_gist         | GiST index support for common types               |
| ltree              | A data type for hierarchical, tree-like data      |
| unaccent           | A text search dictionary that removes accents     |

pg_stat_statements is installed on every database, whatever you choose.

## Choose extensions when you create a database

On the **Create Database** page, open **Advanced Settings** and use **Extensions**.
pg_stat_statements and vector are already chosen. To add another, choose it in **Select
extensions**; **Search extensions** finds one by name.

The extensions you choose are installed in `defaultdb`, the database that the connection details
point to, when the database is created. For the rest of the create page, see [Create a
database](/tir/tir-dbaas/how-to/create-a-database/).

## Add extensions to an existing database

1. Choose **Edit** in the database's row menu on the **Manage Databases** list, or in the three-dot
   menu on its details page. While the database is **Running**, **Extensions** under **Configuration**
   on the **Overview** tab also has an **Edit** link.
2. Open **Advanced Settings**. In **Extensions**, choose the ones you want to add. Those already on
   the database are marked "(installed)".
3. Select **Update Database**.

TIR adds them while the database keeps running, and **Activity Timeline** records "Extensions added" with the names of the new extensions.

**Edit Database** only adds extensions, so an extension you add stays on the database.

## Check which extensions are installed

While the database is **Running**, **Extensions** under **Configuration** on its **Overview** tab
names the installed extensions. The list leaves out the built-in plpgsql.

If an extension fails to install, **Edit Database** names it and says that its install
failed. For what to do, see [An extension could not be
installed](/tir/tir-dbaas/troubleshooting/tir-dbaas/#an-extension-could-not-be-installed).

To tune PostgreSQL settings as well, see [Use parameter
groups](/tir/tir-dbaas/how-to/use-parameter-groups/). To connect and start using an extension, see
[Connect to a database](/tir/tir-dbaas/how-to/connect-to-a-database/).