Materialize/doc/user/content/sql/alter-connection.md

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title: "ALTER CONNECTION" description: "ALTER CONNECTION allows modifying the value of connection options and rotating secrets associated with connections" menu: main:

parent: 'commands'

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ALTER CONNECTION allows modifying the value of connection options and rotating secrets associated with connections. In particular, you can use this command to:

• Modify the parameters of a connection, such as the hostname to which it points.
• Rotate the key pairs associated with an SSH tunnel connection.

Syntax

{{< diagram "alter-connection.svg" >}}

Field	Use
name	The identifier of the connection you want to alter.
SET...	Sets the option to the specified value.
DROP..., RESET...	Resets the specified option to its default value.
ROTATE KEYS	Rotates the key pairs.

WITH options

Field	Value	Description
VALIDATE	boolean	Whether connection validation should be performed. Not available with ROTATE KEYS. Defaults to true.

Description

SET, RESET, DROP

These subcommands let you modify the parameters of a connection.

• RESET and DROP are synonyms and will return the parameter to its original state. For instance, if the connection has a default port, DROP will return it to the default value.
• All provided changes are applied atomically.
• The same parameter cannot have multiple modifications.

For the available parameters for each type of connection, see CREATE CONNECTION.

ROTATE KEYS

The ROTATE KEYS command can be used to change the key pairs associated with an SSH tunnel connection without causing downtime.

Each SSH tunnel connection is associated with two key pairs. The public keys for the key pairs are announced in the mz_ssh_tunnel_connections system table in the public_key_1 and public_key_2 columns.

Upon executing the ROTATE KEYS command, Materialize deletes the first key pair, promotes the second key pair to the first key pair, and generates a new second key pair. The connection's row in mz_ssh_tunnel_connections is updated accordingly: the public_key_1 column will contain the public key that was formely in the public_key_2 column, and the public_key_2 column will contain a new public key.

After executing ROTATE KEYS, you should update your SSH bastion server with the new public keys:

• Remove the public key that was formely in the public_key_1 column.
• Add the new public key from the public_key_2 column.

Throughout the entire process, the SSH bastion server is configured to permit authentication from at least one of the keys that Materialize will authenticate with, so Materialize's ability to connect is never interrupted.

You must take care to update the SSH bastion server with the new keys after every execution of the ROTATE KEYS command. If you rotate keys twice in succession without adding the new keys to the bastion server, Materialize will be unable to authenticate with the bastion server.

Privileges

The privileges required to execute this statement are:

{{< include-md file="shared-content/sql-command-privileges/alter-connection.md" >}}

Related pages

• CREATE CONNECTION
• SHOW CONNECTIONS