---
id: add-missing-indexes-sessions
name: Add Missing Indexes — Sessions & Coordination Domain
status: completed
depends_on: []
scope: narrow
risk: low
impact: component
level: implementation
---

## Description

W03 (partial): Add missing indexes for sessions and coordination domain tables.

Missing indexes:
- `sessions`: `unq_sessions_slug` — UNIQUE constraint on `slug` not listed (unlike other UNIQUEs)
- `sessions`: `idx_sessions_parent_id` on `(parentId)` — find child sessions of coordinator
- `detections`: `idx_detections_session_id` on `(sessionId)` — find detections for a session (table currently has no indexes at all)
- `mappings`: `idx_mappings_workspace_id` on `(workspaceId)` — workspace-scoped mapping queries

## Acceptance Criteria

- [ ] `table-reference.md` indexes section includes `unq_sessions_slug`, `idx_sessions_parent_id`, `idx_detections_session_id`, `idx_mappings_workspace_id`
- [ ] Per-domain docs (`sessions.md`, `coordination.md`) reference the new indexes
- [ ] `detections` table now has at least one index documented
- [ ] All new indexes have documented purpose (query pattern)

## References

- docs/reviews/storage-architecture-review-2026-04-21.md#W03
- docs/architecture/storage/table-reference.md:87-145
- docs/architecture/storage/sessions.md
- docs/architecture/storage/coordination.md

## Notes

> To be filled by implementation agent

## Summary

> To be filled on completion