diff --git a/UPGRADE.md b/UPGRADE.md
index 939bc94..9b3e801 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -1,5 +1,15 @@
 # Upgrading qbit-assistant
 
+## Index audit (2026-10-14)
+
+Recommended, not required: apply the "Index audit" block at the end of
+`docs/schema-postgres.sql`. It adds six indexes, every one `IF NOT EXISTS`:
+- usage by turn (read on each scheduled run)
+- the three retention date filters (turn events, tool calls, inactive conversations)
+- the two `ON DELETE SET NULL` foreign keys on `assistant_scheduled_run`
+
+No code change.
+
 ## Durable turns (Unreleased)
 
 Apply the **Durable turns** block at the end of `docs/schema-postgres.sql` before
diff --git a/docs/schema-postgres.sql b/docs/schema-postgres.sql
index 46a3ab7..9f410d4 100644
--- a/docs/schema-postgres.sql
+++ b/docs/schema-postgres.sql
@@ -592,3 +592,14 @@ CREATE INDEX assistant_turn_user_status ON assistant_turn (user_id, status);
 -- Check for pre-existing duplicate message.end rows before applying this index.
 CREATE UNIQUE INDEX assistant_turn_event_terminal ON assistant_turn_event (turn_id)
    WHERE event_type = 'message.end';
+
+-- Index audit (2026-10-14): lookup, retention and FK paths with no leading index.
+-- ScheduledTurn.cost reads usage by turn on every scheduled run.
+CREATE INDEX IF NOT EXISTS assistant_usage_turn ON assistant_usage (turn_id);
+-- Retention: deleteTurnEventsBefore, clearToolResultsBefore and listConversationsInactiveSince filter by date.
+CREATE INDEX IF NOT EXISTS assistant_turn_event_create_date ON assistant_turn_event (create_date);
+CREATE INDEX IF NOT EXISTS assistant_tool_call_create_date ON assistant_tool_call (create_date);
+CREATE INDEX IF NOT EXISTS assistant_conversation_modify_date ON assistant_conversation (modify_date);
+-- ON DELETE SET NULL children: deleting a conversation or turn would scan scheduled runs without these.
+CREATE INDEX IF NOT EXISTS assistant_scheduled_run_conversation ON assistant_scheduled_run (conversation_id);
+CREATE INDEX IF NOT EXISTS assistant_scheduled_run_turn ON assistant_scheduled_run (turn_id);