Extract three helpers to remove copy-paste between compact() and
_run_structural_migration():
- _meta_set_on(conn, key, value): static upsert into any connection's
index_meta; _meta_set() now delegates to it
- _create_vec_table(conn, dim): CREATE VIRTUAL TABLE DDL (carries the
nosemgrep annotation)
- _swap_in_compact(compact_path, db_path): close/replace/reconnect
sequence used by both file-swap callers
Also normalises compact() error-path cleanup to unlink(missing_ok=True).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adds versioned schema migration support modelled after PR #12968's LanceDB
approach, adapted for sqlite-vec's file-swap compaction pattern.
- SCHEMA_VERSION = 1 written to index_meta at table creation and preserved
through compact()
- Migration dataclass with from_version, to_version, kind ("structural" or
"re-embed"), description, and an optional apply(src, dst, dim) callable
- MIGRATIONS registry (empty at v1 baseline); add entries and bump
SCHEMA_VERSION when the schema changes
- check_and_run_migrations(): structural migrations run via the same
file-swap as compact() (no re-embed); re-embed migrations return True
so the caller forces a full rebuild
- update_llm_index() calls check_and_run_migrations() under the write lock
before any indexing work
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Fixes the non-AVX2 SIGILL class (#12970) at the root: lancedb is no
longer imported. sqlite-vec 0.1.9 wheels carry no baked SIMD, vec0
metadata columns give parameterized EQ/IN filtering, WAL preserves the
lock-free-reader model, and compact() rebuilds the table because vec0
DELETEs never reclaim space.
Implementation notes vs. the Task 3A draft:
- compact() uses a file-swap approach (new db file + Path.replace) rather
than ALTER TABLE RENAME, which does not cascade to shadow tables in
sqlite-vec 0.1.9 (upstream limitation).
- Bloat is tracked via a cumulative total_inserts counter in index_meta
because the _rowids shadow table does not accumulate deleted rows in
0.1.9 (contrary to the design doc assumption from #54).
- None distances from the zero-vector cosine edge case are mapped to
similarity 0.0 rather than raising TypeError.
- Test suite updated accordingly: _bloat_ratio reads index_meta instead
of _rowids; seed collision in force-compact test fixed (seed=100.0).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
stumpylog
