PostgreSQL Event Triggers without superuser access

AI summary

This article explains how the supautils extension enables non-superuser roles to create event triggers in managed Postgres environments. By leveraging Postgres Utility and Function Manager hooks, the extension safely elevates privileges during creation and prevents privilege escalation by intercepting trigger execution for superuser or reserved roles.

Key points

• Event triggers in Postgres normally require superuser access, creating security risks in managed cloud environments.
• Utility hooks (ProcessUtility_hook) allow for controlled privilege escalation during DDL operations by proxying superuser capabilities.
• Function Manager hooks (fmgr_hook) can be used to prevent malicious privilege escalation by intercepting and suppressing trigger execution for specific roles.
• Safely implementing user-defined event triggers requires ensuring they do not execute with elevated privileges when triggered by superuser sessions.