audit_diff

File: schema/functions/audit_diff.yaml · returns trigger · plpgsql · SECURITY INVOKER · VOLATILE

The AFTER INSERT/UPDATE/DELETE trigger function for the audit_log mixin (20_audit_log_diff). Writes field-level change history to the audit_log table, reading the actor id from the actor_guc parameter.

Behavior

• No actor set → the trigger returns early and writes nothing. Bootstrap activity is not audit-worthy, and audit_log.changed_by is NOT NULL, so there is no actor to record.
• PK discovery — the primary-key column is found from pg_index and cast to text, so both serial-int and text PKs are supported.
• INSERT → one __row__ row, new_value = 'created'.
• DELETE → one __row__ row, previous_value = 'existed', new_value = 'hard-deleted'.
• UPDATE → the OLD and NEW rows are compared as jsonb; one history row is written per column whose value is IS DISTINCT FROM its old value.

Skipped columns

These stamp columns are never diffed (they’d be noise on every update):

created_at, created_by, updated_at, updated_by, deleted_at

deleted_at is skipped as a per-column diff, but its transitions still produce lifecycle markers:

Transition	__row__ row
deleted_at NULL → set	active → archived
deleted_at set → NULL	archived → restored

The __row__ sentinel

Lifecycle transitions (created / archived / restored / hard-deleted) have no specific column diff, so they are recorded against the sentinel field value '__row__'. Per-column changes use the real column name as field.