Milvus adapter end-to-end tire-kicking session (SPEC-81 verification)

[phernandez]

Tracking issue for the manual end-to-end verification session of the Milvus vector-index
adapter (SPEC-81; PRs #1141, #1158, #1185). There is no automated end-to-end coverage —
every Milvus test uses fakes or bare Milvus Lite — so this session exercises the real
stack: Postgres + Milvus Lite through sync → manifest → search, adapter switches, reindex,
and failure drills, using a realistic 200+ note corpus.

Session checklist

• Three-way baseline matrix: same corpus + embedding model through sqlite-vec /
  pgvector / Milvus Lite; compare top-5 membership, cosine scores, hybrid rankings,
  latency (~10 known-answer queries)
• Fresh Milvus enablement via bm reindex --embeddings; collection naming verified
• The silent-degraded window: config flipped to milvus before reindex → vector returns
  0, hybrid silently degrades to FTS (documented UX finding)
• Manifest honesty: vector_index ownership flip; stale pgvector rows accounting
• Switch-back fail-closed: SemanticVectorIndexExtensionError capture + recovery UX
• Failure drills: missing extra, bad URI shapes, unreachable server (index vs query
  time, timeout/lock-hold), dimension mismatch refusal
• Restart persistence (fix(core): load existing Milvus collections after restart #1185 in real flow)
• Reranker + Milvus interplay (sanity + latency)
• Redaction smoke (milvus_token/milvus_uri in config output)

Deliverables

• Results recorded as a Basic Memory note with conclusions (dogfooding), linked here
• Issues filed for any bugs/UX findings
• Docs-gap follow-up list (local-Postgres quickstart, fresh-switch reindex step, .db
  URI requirements, Lite milvus_database caveat, degraded-window behavior)
• SPEC-81 updated: draft → implemented-with-deviations (in-core extra, entry-point
  registry removed, namespace = DB-locator hash, collection identity excludes model/dims)

[claude]

Claude finished @phernandez's task in 51s —— View job

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Triage

Type: Enhancement — this is a tracking issue for a manual, human-driven verification session (not a code defect report), covering the Milvus vector-index adapter shipped in SPEC-81 (#1141, #1158, #1185).

Component: Search/indexing (vector index adapters — sqlite-vec / pgvector / Milvus Lite, bm reindex, semantic search). Not Cloud-specific: the checklist runs local Postgres + Milvus Lite and doesn't touch Cloud-only surfaces, so no cloud label applied.

Priority: Medium — there's no automated end-to-end coverage for the Milvus path today (tests use fakes or bare Milvus Lite), so this closes a real verification gap, but nothing is reported broken yet.

Complexity: Complex — a full manual session across a 200+ note corpus: three-way baseline comparison (sqlite-vec/pgvector/Milvus), fresh-enablement and reindex flows, failure-mode drills (missing extra, bad URI, unreachable server, dimension mismatch), restart persistence, reranker interplay, and redaction checks, plus SPEC-81 status/doc follow-ups as deliverables.

Duplicates: None found — no other open issue references Milvus, SPEC-81, or a similar verification session.

No reproduction steps needed (this is a planned verification session, not a bug report). Labeled enhancement.

[phernandez]

Session complete — all checklist items executed. Headline: the adapter core is solid (identical vector rankings and 4-decimal score agreement across sqlite-vec / pgvector / Milvus Lite on a 222-entity corpus; all fail-closed paths fire correctly, dimension-mismatch message is exemplary). All findings are operator-surface: #1236 (silent degraded window when the configured index has no ready manifest rows), #1237 (reindex --embeddings exits 0 on 100% embed failure with the guard message log-only), #1238 (docs bundle: local-Postgres quickstart, fresh-switch reindex step, .db-is-a-directory, Lite milvus_database caveat, stale pgvector rows). Full log with per-test verdicts recorded in Basic Memory: dev/testing/'Milvus Adapter Tire-Kick Session 2026-08-11'. SPEC-81 updated to implemented-with-deviations with the resolved open questions.