First VectorStore implementation. Per-model Lance tables under
config.storage.vector_dir, two-phase upsert (SQLite-pending → Lance
MergeInsert → SQLite-committed) with crash-safe retry, search via
cosine distance with the spec's score-shift (preserves negative
similarity ranking signal that clamping would crush).
V003 migration:
- Adds status (CHECK constraint pending|committed|tombstone, default
pending) and vector_committed columns to embedding_records.
- BEFORE DELETE trigger on chunks flips dependent rows to tombstone.
Currently overshadowed by V001's ON DELETE CASCADE FK; trigger UPDATE
runs first then row vanishes via CASCADE. Spec-faithful tombstone
preservation requires recreating embedding_records to drop the
CASCADE — deferred to a P+ migration since no production rows exist
yet (P3-3 is the first writer). V003 SQL comment explains.
LanceVectorStore:
- ensure_table is idempotent: opens existing or creates with the
Arrow schema (chunk_id, doc_id, embedding FixedSizeList<Float32,
dim>, model_id, embedding_version, text, heading_path, created_at).
- IndexId computed via id_for_index with collection="chunk_embeddings",
index_kind="flat", params_hash = blake3(descriptor JSON). Schema
bumps automatically rotate the IndexId.
- upsert: phase-1 INSERT OR REPLACE INTO embedding_records (status=
'pending') in a single SQLite tx; phase-2 Lance MergeInsert keyed
on chunk_id (idempotent re-run); phase-3 UPDATE status='committed',
vector_committed=1. If phase-2 fails the rows stay 'pending' and
the next upsert call retries idempotently.
- search joins embedding_records WHERE status='committed' so partial-
write rows never surface. Cosine distance from Lance ∈ [0, 2] →
similarity = 1 - distance ∈ [-1, 1] → score = (similarity + 1)/2 ∈
[0, 1]. NaN coerced to 0 with tracing::warn. Filter by SearchFilters
via SqliteStore::filter_chunks (added in this commit).
- Sync trait + async LanceDB bridged by an embedded current-thread
tokio runtime. Doc-comment on the struct flags the "do NOT call
from inside another tokio runtime" panic (block_on cannot nest).
kb-app's job scheduler is sync today.
kb-store-sqlite additions:
- pub fn put_embedding_records_pending(&[EmbeddingRecordRow]) — phase-1
INSERT OR REPLACE (status='pending', vector_committed=0).
- pub fn mark_embedding_records_committed(&[EmbeddingId]) — phase-3
single UPDATE … WHERE embedding_id IN (?, ?, …) via
params_from_iter, guarded by WHERE status='pending' so tombstones
don't get clobbered.
- pub fn filter_chunks(&[ChunkId], &SearchFilters) → Vec<ChunkId>
consolidates the JOIN against documents/document_tags/
embedding_records + path_glob via globset. Lets kb-store-vector
honor SearchFilters without depending on rusqlite or globset
directly. (kb-search's filter logic is structurally different —
interleaved with the FTS5 SELECT — so it stays as-is for now;
consolidation is a P+ refactor.)
- 4 new unit tests cover the phase-1 round-trip, empty batch,
replay reset of pending rows, and the WHERE-status-pending guard.
Tests:
- 9 lib unit tests in kb-store-vector covering paths/sanitization,
arrow_batch dim validation + descriptor hash, bm25-style cosine
score shift math.
- 4 new kb-store-sqlite unit tests on filter_chunks (committed-only,
tags/lang/trust/path_glob, order preservation, empty input).
- 4 new kb-store-sqlite unit tests on the embedding_records helpers.
- 8 integration tests in upsert_search.rs and 1 snapshot test marked
#[ignore = "requires AVX-capable hardware (LanceDB)"]. They invoke
require_avx_or_panic() at the top of each body so a missing-AVX
--ignored run fails loudly instead of silently passing. This dev
host (qemu64 model) lacks AVX so these were NOT exercised end-to-
end here — first CI lane on AVX hardware will validate them.
- Snapshot fixture tests/fixtures/vector/run-1.json is a placeholder
with an _comment marker. Snapshot test panics until the placeholder
is replaced via KB_UPDATE_SNAPSHOTS=1 on AVX hardware.
- Workspace 241 passed, 19 ignored, 0 failed; cargo clippy --workspace
--all-targets -- -D warnings clean.
Allowed deps respected (kb-core, kb-config, kb-store-sqlite, lancedb,
arrow + arrow-array + arrow-schema, serde, serde_json, tracing,
thiserror) plus forced waivers — anyhow (trait return type), tokio
+ futures (LanceDB async-only API), blake3 (params_hash). rusqlite
and globset are NOT direct deps of kb-store-vector — confirmed via
cargo metadata --no-deps. rusqlite stays in [dev-dependencies] for
the test fixture seeder only.
Out of scope: IVF/PQ index tuning (P+), image vectors (P6), kb-app
embed_index orchestration (P3-4 facade).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
altair823
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