All Products
Search

This Product

    PolarDB:DROP SUBSCRIPTION

    Document Center

    PolarDB:DROP SUBSCRIPTION

    Last Updated:Mar 28, 2026

    Removes a subscription from the database cluster.

    Prerequisites

    Before you begin, ensure that you have:

    • Superuser privileges on the database cluster

    Synopsis

    DROP SUBSCRIPTION [ IF EXISTS ] name [ CASCADE | RESTRICT ]

    Parameters

    ParameterDescription
    nameThe name of the subscription to drop.
    CASCADE | RESTRICTNo effect. These keywords are accepted for SQL compatibility but perform no action, as subscriptions have no dependencies.

    Usage notes

    Replication slot handling

    When you drop a subscription that is associated with a replication slot on the remote host (the normal state), DROP SUBSCRIPTION connects to the remote host and drops the replication slot and any remaining table synchronization slots. This releases the resources allocated for the subscription on the remote host.

    The command fails if any of the following conditions are true:

    • The remote host is unreachable.

    • The remote replication slot cannot be dropped.

    • The remote replication slot does not exist or never existed.

    Transaction block restriction

    DROP SUBSCRIPTION cannot run inside a transaction block when the subscription is associated with a replication slot. To disassociate the subscription from the slot before dropping, first disable the subscription by running ALTER SUBSCRIPTION ... DISABLE, and then disassociate it from the replication slot by running ALTER SUBSCRIPTION ... SET (slot_name = NONE).

    Warning

    If orphaned replication slots are left on the remote host, they continue to reserve Write-Ahead Log (WAL) space and can eventually fill the disk.

    Drop a subscription when the remote host is unreachable

    If DROP SUBSCRIPTION fails because the remote host is unreachable or the replication slot cannot be dropped, follow these steps:

    1. Disable the subscription.

      ALTER SUBSCRIPTION <subscription_name> DISABLE;

    2. Disassociate the subscription from the replication slot.

      ALTER SUBSCRIPTION <subscription_name> SET (slot_name = NONE);

    3. Drop the subscription.

      DROP SUBSCRIPTION <subscription_name>;

    After step 3, DROP SUBSCRIPTION no longer attempts any actions on the remote host. However, if the remote replication slot still exists, drop it and any related table synchronization slots manually to prevent WAL accumulation.

    Example

    Drop a subscription:

    DROP SUBSCRIPTION mysub;

    See also