---
issue: 122
title: "Backend: missing compound index for seller-visibility purchase-request query"
severity: low
domain: Marketplace
labels: [performance, backend, database]
status: open
created: 2026-05-30
source: Full Codebase Audit 2026-05-30
---

# Backend: missing compound index for seller-visibility purchase-request query

**Severity:** low
**Domain:** Marketplace
**Labels:** performance, backend, database

## Description

`PurchaseRequestService.ts:267` queries PurchaseRequests for the public marketplace feed filtering by `status` and `isPublic`. Without a compound index, this requires a collection scan on every marketplace page load.

## Options

1. Add `{ status:1, isPublic:1 }` (and possibly `createdAt:-1`) compound index.
2. Add a covering index including sort fields.
3. Profile actual query plans first, then index.

## Recommendation

Add a `{ status:1, isPublic:1, createdAt:-1 }` compound index after confirming the dominant query shape. Indexing has write-cost trade-offs.

## Affected Files

- `backend/src/services/marketplace/PurchaseRequestService.ts:267`
- `backend/src/models/PurchaseRequest.ts` — index definition

## References

- [Full Codebase Audit 2026-05-30](../09%20-%20Audits/Full%20Codebase%20Audit%20-%202026-05-30.md) — DEC-43