> For the complete documentation index, see [llms.txt](https://docs.greennode.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.greennode.ai/vdb/relational-database-service-rds/postgresql-standalone/vdb-postgresql-standalone-extensions.md).

# Extensions for PostgreSQL Standalone

PostgreSQL is renowned for its flexibility. You can extend its core functionality with various Extensions.

By default, when you create a database with vDB PostgreSQL, several extensions are already enabled (listed below). You can also manually enable additional extensions as needed.

***

## 1. Extensions Enabled by Default

For PostgreSQL, newly created databases will have extensions enabled from the **template1** database.

After creating a database, you can check the enabled extensions by running:

```sql
\dx
```

or

```sql
select * from pg_extension;
```

Below is the list of extensions enabled by default:

| No | Name          | Description                                                         |
| -- | ------------- | ------------------------------------------------------------------- |
| 1  | plpgsql       | PL/pgSQL procedural language                                        |
| 2  | btree\_gin    | Support for indexing common datatypes in GIN                        |
| 3  | btree\_gist   | Support for indexing common datatypes in GiST                       |
| 4  | citext        | Data type for case-insensitive character strings                    |
| 5  | cube          | Data type for multidimensional cubes                                |
| 6  | dict\_int     | Text search dictionary template for integers                        |
| 7  | dict\_xsyn    | Text search dictionary template for extended synonym processing     |
| 8  | hstore        | Data type for storing sets of (key, value) pairs                    |
| 9  | isn           | Data types for international product numbering standards            |
| 10 | lo            | Large Object maintenance                                            |
| 11 | ltree         | Data type for hierarchical tree-like structures                     |
| 12 | pg\_trgm      | Text similarity measurement and index searching based on trigrams   |
| 13 | postgis       | PostGIS geometry, geography, and raster spatial types and functions |
| 14 | postgres\_fdw | Foreign-data wrapper for remote PostgreSQL servers                  |
| 15 | unaccent      | Text search dictionary that removes accents                         |
| 16 | vector        | Vector data type and ivfflat and hnsw access methods                |

**Note:** If you want to create a completely blank database, use **template0**.

```sql
CREATE DATABASE dbname TEMPLATE template0;
```

## 2. Extensions You Can Enable Manually

You can enable an Extension by running:

```sql
CREATE EXTENSION <extension_name>;
```

| Name                     | Description                                                                              |
| ------------------------ | ---------------------------------------------------------------------------------------- |
| fuzzystrmatch            | Determine similarities and distance between strings                                      |
| intarray                 | Functions, operators, and index support for 1-D arrays of integers                       |
| pgcrypto                 | Cryptographic functions                                                                  |
| postgis\_tiger\_geocoder | PostGIS tiger geocoder and reverse geocoder (requires fuzzystrmatch to be enabled first) |
| seg                      | Data type for representing line segments or floating-point intervals                     |
| tablefunc                | Functions that manipulate whole tables, including crosstab                               |
| tcn                      | Triggered change notifications                                                           |
| tsm\_system\_rows        | TABLESAMPLE method which accepts number of rows as a limit                               |
| tsm\_system\_time        | TABLESAMPLE method which accepts time in milliseconds as a limit                         |
| uuid-ossp                | Generate universally unique identifiers (UUIDs)                                          |

***

## 3. Notes

* The **vector** extension is only available for vDB instances created from **01/08/2024** onwards.
* To enable it on instances created before that date, please contact **GreenNode Cloud Support**.