-- ============================================================
-- Omika Diagnostic Center -- 004_diagnostics_retention.sql (Phase 5C.2C)
-- PostgreSQL : moindre privilège pour la rétention diagnostic.
-- ============================================================
-- TO RUN ON SRV-OMIKA as PostgreSQL superuser (e.g. psql -U postgres).
-- DO NOT run from the development PC.
--
-- Guarantees :
--   - PostgreSQL 18 compatible.
--   - Idempotent : re-running is a no-op (GRANT is idempotent).
--   - Non destructive : NO DROP, NO DELETE/TRUNCATE, NO role/object removal.
--   - NO password, NO secret.
--
-- Context (Phase 5C.2C) : the retention loop (DiagnosticRetentionWorker) purges
-- diagnostic_event by BOUNDED batches :
--
--   DELETE FROM diagnostic_event
--   WHERE id IN (
--       SELECT id FROM diagnostic_event
--       WHERE timestamp_utc < @cutoff
--       ORDER BY timestamp_utc ASC, id ASC
--       LIMIT @batchSize
--   )
--
-- This SQL requires :
--   * DELETE on diagnostic_event (the target of the DELETE) ;
--   * SELECT on diagnostic_event (the sub-query reads the table).
--
-- The worker role (omika_diagnostics_worker) currently holds only INSERT +
-- USAGE sequence (see 003). Least privilege : grant ONLY SELECT + DELETE.
-- NO UPDATE, NO TRUNCATE, NO DDL, NO privilege on telemetry_metric_hourly.
-- ============================================================

GRANT SELECT, DELETE ON TABLE diagnostic_event TO omika_diagnostics_worker;

-- ============================================================
-- END 004. Apply order on server : 001 -> 002 -> 003 -> 004.
-- No server action is performed by the development PC.
-- ============================================================