# Raw Upsert Idempotency Prep — PREP-EXCITITOR-CORE-AOC-19-003-BLOCKED-ON-19

Status: Draft (2025-11-20)
Owners: Excititor Core Guild
Scope: Document the idempotent raw upsert and versioning requirements once linkset extraction (19-002) is defined.

## Pending inputs
- Linkset schema and conflict markers from 19-002.
- Storage model choice (Mongo vs Postgres) and required unique keys per tenant/advisory/component/version_range.

## Proposed rules (draft)
- Unique key: `(tenant_id, advisory_id, component_purl, version_range, source)`; store a monotonic `revision` and `ingested_at` (UTC) for traceability.
- Idempotency: compute content hash over canonicalized payload; if identical, no-op; otherwise append new revision with `supersedes` pointer.
- Append-only log: keep prior revisions for audit; consumers read latest by hash or highest revision per key.
- Determinism: canonical JSON ordering; stable sorting by `(tenant_id, advisory_id, component_purl, version_range, revision)`.

## Handoff
Use this as the prep artefact for PREP-EXCITITOR-CORE-AOC-19-003-BLOCKED-ON-19. Finalize once 19-002 freezes schema and storage choice; then wire migrations/indexes accordingly.