Duplicate requests

What it is

Duplicate handling defines behavior when the same action arrives again.

When to use it

Expect retries, double clicks, and repeated webhook delivery.

Syntax

unique event ID + payload comparison + replay policy

Example

CREATE UNIQUE INDEX provider_events_unique
ON provider_events (provider, event_id);
-- Validate signature first.
-- Persist processing/result atomically with business changes.

Common mistakes

Different keys can still represent duplicate business operations; add appropriate business uniqueness too.

Related topics