---
title: "postgres_fdw extension"
url: "https://docs.yugabyte.com/stable/additional-features/pg-extensions/extension-postgres-fdw/"
---

# postgres_fdw extension

Using the postgres_fdw extension in YugabyteDB

The [postgres\_fdw](https://www.postgresql.org/docs/15/postgres-fdw.html "postgres_fdw") module provides the foreign-data wrapper postgres\_fdw, which can be used to access data stored in external PostgreSQL or YugabyteDB servers.

In v2026.1.2 and later, the extension is installed into `pg_catalog` during cluster initialization (and on upgrade) so [cluster-wide database views](/stable/explore/observability/cluster-wide-db-views/ "cluster-wide database views") can be created by default. `CREATE EXTENSION IF NOT EXISTS postgres_fdw` is harmless if you run it; if the extension is already installed, it reports `NOTICE: extension "postgres_fdw" already exists, skipping`:

```plpgsql
CREATE EXTENSION IF NOT EXISTS postgres_fdw;
```

To connect to a remote PostgreSQL database, create a foreign server object. Specify the connection information (except the username and password) using the `OPTIONS` clause:

```plpgsql
CREATE SERVER my_server FOREIGN DATA WRAPPER postgres_fdw
    OPTIONS (host 'host_ip', dbname 'external_db', port 'port_number');
```

For a remote YugabyteDB cluster, include [server\_type](#server-type-option "server_type") when you create the server.

Specify the username and password using `CREATE USER MAPPING`:

```plpgsql
CREATE USER MAPPING FOR mylocaluser SERVER my_server OPTIONS (user 'remote_user', password 'password');
```

You can now create foreign tables using `CREATE FOREIGN TABLE` and `IMPORT FOREIGN SCHEMA`:

```plpgsql
CREATE FOREIGN TABLE table_name (colname1 int, colname2 int) SERVER my_server OPTIONS (schema_name 'schema', table_name 'table');
IMPORT FOREIGN SCHEMA foreign_schema_name FROM SERVER my_server INTO local_schema_name;
```

You can execute `SELECT` statements on the foreign tables to access the data in the corresponding remote tables.

## server\_type option

`server_type` is a YugabyteDB addition to the server options `postgres_fdw` accepts. It tells the wrapper what kind of server is behind the foreign tables, which decides how rows are identified and, for one value, how the query runs.

| Value                 | Meaning                                                                                          |
|-----------------------|--------------------------------------------------------------------------------------------------|
| `postgreSQL`          | The remote server is PostgreSQL. Rows are identified by `ctid`. Used when the option is omitted. |
| `yugabyteDB`          | The remote server is another YugabyteDB cluster. Rows are identified by `ybctid`.                |
| `federatedYugabyteDB` | There is no remote server. Each foreign table is read from every node of the local cluster.      |

Set the option when you create the server.

For example, create a server for a remote YugabyteDB cluster:

```plpgsql
CREATE SERVER my_server FOREIGN DATA WRAPPER postgres_fdw
    OPTIONS (server_type 'yugabyteDB', host 'host_ip', dbname 'external_db', port 'port_number');
```

The value is case-insensitive. If you don't specify a server, the system defaults to `postgreSQL` and reports the following:

```output
NOTICE:  no server_type specified. Defaulting to PostgreSQL.
HINT:  Use "ALTER SERVER ... OPTIONS (ADD server_type '<type>')" to explicitly set server_type.
```

`federatedYugabyteDB` doesn't take `host`, `dbname`, or `port`, and doesn't need `CREATE USER MAPPING` because the target nodes come from the cluster's own tablet server list and each node is reached over an internal connection. YugabyteDB creates one such server, `yb_global_views_server`, and uses it for [cluster-wide database views](/stable/explore/observability/cluster-wide-db-views/ "cluster-wide database views"). You don't need to create this server yourself; it is equivalent to:

```plpgsql
CREATE SERVER yb_global_views_server FOREIGN DATA WRAPPER postgres_fdw
    OPTIONS (server_type 'federatedYugabyteDB');
```

To query per-node statistics views across every live YB-TServer from a single session, see [Cluster-wide database views](/stable/explore/observability/cluster-wide-db-views "Cluster-wide database views").