draft initial rdbms support policy

docs/self-managed/concepts/rdbms-support-policy.md

@@ -0,0 +1,53 @@
+---
+id: rdbms-support-policy
+title: RDBMS version support policy
+description: Defines Camunda’s official RDBMS version support policy, including supported databases, version adoption rules, and JDBC driver guidance.
+---
+
+Camunda offers a support policy for relational databases (RDBMS) in Self-Managed Camunda 8 and Camunda 8 Run, including supported versions, adoption and deprecation rules, and JDBC driver guidance.
+
+:::caution work in progress
+The RDBMS support policy is a work in progress, content can change until completion in a future alpha release.
+:::
+
+## Supported RDBMS
+
+The following RDBMS databases are supported:
+
+| Database             | Supported versions |
+| :------------------- | :----------------- |
+| PostgreSQL           | 14, 15             |
+| MariaDB              | 10.6, 10.11        |
+| MySQL                | 8.0                |
+| Microsoft SQL Server | 2019, 2022         |
+| Oracle               | 19c (LTS), 21c     |
+| H2                   | 2.x                |
+
+:::info
+Changes to supported versions are announced in [release notes](/reference/announcements-release-notes/890/890-release-notes.md).
+:::
+
+## New version support
+
+New versions are added based on:
+
+- **Vendor release timeline:** Must be officially released by the vendor.
+- **Availability window:** Must be available at least three months before the next minor Camunda release.
+- **Testing requirements:** Must be fully tested and validated across Camunda components.
+
+:::note
+Exceptions may be approved by engineering for strategic reasons or customer demand.
+:::
+
+## Version support deprecation/removal
+
+Versions are deprecated and removed based on:
+
+- **Vendor end-of-support (EoS):** Removed when EoS occurs or will occur within six months.
+- **Migration notice:** Adequate notice provided to customers via release notes.
+- **Exceptions:** Engineering may extend support in special cases.
+
+## JDBC driver policy
+
+- Camunda supports the latest vendor-compatible JDBC driver for each supported RDBMS. Customers should use the latest compatible driver.
+- Driver version details are not strictly fixed unless required for compatibility.

sidebars.js

@@ -1656,6 +1656,7 @@ module.exports = {
               ],
             },
             "self-managed/concepts/secondary-storage/managing-secondary-storage",
+            "self-managed/concepts/rdbms-support-policy",
           ],
         },
         {