> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-sync-clickhouse-operator-docs-7e82242.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Upgrades

> How PostgreSQL version upgrades work in ClickHouse Managed Postgres

export const PrivatePreviewBadge = () => {
  return <div className="privatePreviewBadge">
            <div className="privatePreviewIcon">
            <svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path d="M5.33301 6.66667V4.66667V4.66667C5.33301 3.194 6.52701 2 7.99967 2V2C9.47234 2 10.6663 3.194 10.6663 4.66667V4.66667V6.66667" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
                <path d="M8.00033 9.33337V11.3334" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
                <path fillRule="evenodd" clipRule="evenodd" d="M11.333 14H4.66634C3.92967 14 3.33301 13.4033 3.33301 12.6666V7.99996C3.33301 7.26329 3.92967 6.66663 4.66634 6.66663H11.333C12.0697 6.66663 12.6663 7.26329 12.6663 7.99996V12.6666C12.6663 13.4033 12.0697 14 11.333 14Z" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
            </svg>
        </div>
            {'Private preview in ClickHouse Cloud'}
        </div>;
};

Managed Postgres handles PostgreSQL version upgrades to keep your instances secure and up to date. Both minor and major version upgrades are supported with minimal disruption.

<h2 id="minor-version-upgrades">
  Minor version upgrades
</h2>

Minor version upgrades (e.g., 16.4 to 16.5) include bug fixes and security patches. These are performed via failover and typically result in only a brief disconnect, often lasting just a few seconds.

For instances with [standbys](/products/managed-postgres/high-availability) enabled, the upgrade is applied to the standby first, followed by a failover to minimize downtime.

<h2 id="major-version-upgrades">
  Major version upgrades
</h2>

Major version upgrades (e.g., 16.x to 17.x) also involve only a few seconds of downtime, following a similar failover-based approach.

<h2 id="maintenance-windows">
  Maintenance windows
</h2>

Managed Postgres supports maintenance windows so that upgrades and other maintenance operations can be scheduled at a time that's least disruptive to your workload. UI support for configuring maintenance windows is coming soon. In the meantime, contact [support](https://clickhouse.com/support/program) to set up a maintenance window for your instance.