Merge pull request #6283 from ClickHouse/andreyc/update-docs

Reworked "upgrades" section of the Managed Postgres docs for Beta

Author: achudnovskij

docs/cloud/managed-postgres/upgrades.md

@@ -13,16 +13,26 @@ import BetaBadge from '@theme/badges/BetaBadge';
 
 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.
 
-## Minor version upgrades {#minor-version-upgrades}
+## Maintenance updates {#maintenance-updates}
 
-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.
+Regular maintenance in the PostgreSQL instances includes the following:
 
-For instances with [standbys](/cloud/managed-postgres/high-availability) enabled, the upgrade is applied to the standby first, followed by a failover to minimize downtime.
+-   Minor version upgrades (e.g., 17.4 to 17.5) include bug fixes and PostgreSQL engine security patches.
+-   Managed Service features. Improvements to native CDC, observability, pg_clickhouse, and other extensions.
+-   Operating system and system components patches. Including security fixes, efficiency, and other improvements.
 
-## Major version upgrades {#major-version-upgrades}
+These are performed via failover and typically result in only a brief disconnect, often lasting just a few seconds.
 
-Major version upgrades (e.g., 16.x to 17.x) also involve only a few seconds of downtime, following a similar failover-based approach.
+For instances with [standbys](/cloud/managed-postgres/high-availability) enabled, the upgrade is applied to the standby first, followed by a failover to minimize downtime.
 
 ## Maintenance windows {#maintenance-windows}
 
-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.
+Default maintenance window is 14:00 to 16:00 UTC on Sunday.
+Expected downtime is less than 1 minute within the window.
+
+For Enterprise Tier organizations, 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 and API 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.
+
+## Major version upgrades {#major-version-upgrades}
+
+Major version upgrades (e.g., 17.x to 18.x) via UI and API are coming soon.
+In the meantime, contact [support](https://clickhouse.com/support/program) to upgrade your Managed Postgres instance.