adityamukho · May 17, 2026 · May 17, 2026 · May 17, 2026
@@ -5,6 +5,72 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Wave 3 Reliability — 2026-05-17
+
+### Summary
+
+Six PRs hardening the v1.0.0 codebase: WAL fault injection, storage/migration resilience, query correctness (property-based + coverage gates), long-haul smoke testing, and XTDB/Datomic semantic compatibility. No API changes, no file-format changes, no new runtime dependencies.
+
+**PR #254 — #209 + #210 + #214: WAL Fault Injection**
+
+- `FaultInjectingBackend` (`#[cfg(test)]`-only wrapper around `StorageBackend`) — configurable write-fail, flush-fail, read-fault injection
+- 9 new WAL fault tests: write-fail propagation, flush-fail without data corruption, read-fault on WAL replay, CRC corruption discard, checkpoint atomicity under backend failure, partial checkpoint recovery via WAL replay, multi-writer serialisation, concurrent write+checkpoint, backend error propagation as `Err` not panic
+
+**PR #257 — #215 + #216 + #217: Storage & Migration Resilience**
+
+- `tests/migration_matrix_test.rs` — 5 migration tests: v7 round-trip, v3 empty migrate, corrupt magic returns `Err`, unsupported version returns `Err`, WAL replay idempotent
+- `tests/index_corruption_test.rs` — 5 corruption-resilience tests: checksum mismatch triggers index rebuild, btree leaf/internal corrupt pages return `Err` without panic, root pointer mismatch handled, non-critical corruption still serves queries on good data
+- 5 new concurrency stress tests in `tests/concurrency_test.rs`: stress readers during writer, failed write then success, rollback after partial work, open/write/checkpoint/query loop per thread, nightly stress loop (`#[ignore]`)
+
+**PR #256 — #212 + #213 + #219: Property-Based Testing & Coverage Gates**
+
+- `tests/property_test.rs` (proptest, `cfg(not(wasm32))`): 3 property tests — EAV model correctness vs naive reference evaluator, bi-temporal monotonicity, retract visibility invariant
+- `.github/workflows/coverage-gates.yml` — per-module branch coverage thresholds; CI fails if coverage drops below gate
+
+**PR #258 — #220: Long-Haul Smoke Suite**
+
+- `tests/smoke_test.rs` (`#[ignore]` nightly): `smoke_large_graph_10_cycles` — 500 entities × 10 attributes × 10 update cycles; 7 invariants: active count (333), retracted count, fact count bounds, temporal snapshot integrity, prepared query consistency, recursive rule transitive closure, WAL checkpoint round-trip
+- `.github/workflows/smoke.yml` — nightly 5am UTC, 15-min timeout, runs `--include-ignored`
+
+**PR #259 — #221: XTDB & Datomic Compatibility Corpus**
+
+- `tests/xtdb_compat_test.rs` — 10 semantic ports (Apache 2.0): EAV, tx-time `:as-of`, valid-time `:valid-at`, retraction (current + historical), Datalog join, negation, recursive rules, parameterised queries, combined bi-temporal
+- `tests/datomic_compat_test.rs` — 9 independently written semantic ports: datom model, multi-entity attribute, tx-time `:as-of`, retract-entity, multi-variable `:find`, ground-value binding, parameterised query (prepared), named reusable rules, predicate expression filter
+
+### Tests
+
+935 tests passing (943 total, 8 ignored: 6 or+neg-cycle stratification doc tests, 1 nightly concurrency stress, 1 nightly smoke).
+
+---
+
+## Wave 2 Optimizer & Benchmarks — 2026-05-16
+
+### Summary
+
+Three optimisation PRs extending the Wave 1 performance work. No API changes, no file-format changes, no new runtime dependencies. Test count unchanged at 850.
+
+**PR #249 — #207 + #206: Predicate Push-Down & Mixed Rule Optimization**
+
+- `optimizer::plan()` extended to accept `Expr` (predicate/arithmetic) clauses; they are interleaved at the earliest position where all their variables are bound, minimising intermediate binding sets
+- `StratifiedEvaluator` gains mixed-rule path: when a rule stratum contains both positive-only rules and rules with `not`/`not-join`, the evaluator now evaluates all positive rules first and applies negation filters in a second pass within the same stratum — eliminates a class of ordering-dependent bugs in cross-stratum negation
+
+**PR #251 — #205: Cost-Based `not`/`or` Ordering**
+
+- `optimizer::plan()` assigns selectivity estimates to `not`/`not-join` and `or`/`or-join` clauses; they are sorted after their ground-variable producers but before unconstrained pattern scans
+- `not`/`not-join` blocks placed after the patterns that produce their join variables (was: end of plan regardless); `or`/`or-join` blocks placed by estimated output cardinality
+
+**PR #253 — #229: SIMD Benchmarking & Crossover Analysis**
+
+- `benches/simd_helpers.rs`: `valid_time_filter_simd`, `as_of_filter_simd`, `sum_simd_i64` — portable SIMD kernels using `wide::i64x4` / `u64x4`
+- Criterion benchmark groups: `simd_temporal`, `simd_as_of`, `simd_aggregate` — scalar vs. SIMD crossover analysis at 1K–1M facts
+- Analysis result: SIMD crossover occurs at ~8K–16K facts per query; scalar path preferred below that threshold; SIMD integration deferred to post-1.0 backlog pending real-workload profiling
+
+### Tests
+
+850 tests passing (844 passing + 6 ignored: confirmed `or`+neg-cycle stratification bug, deferred to post-1.0 backlog). All Wave 2 PRs are optimisations; no new integration tests added.
+
+---
+
 ## Wave 1 Performance — 2026-05-15
 
 ### Summary

@@ -167,14 +167,14 @@ Auto-migrates v1/v2/v3/v4/v5/v6 → v7 on open/checkpoint.
 
 ## Test Coverage
 
-**850 tests passing** (unit + integration + doc).
+**935 tests passing** (unit + integration + doc).
 See `TEST_COVERAGE.md` for the full per-file breakdown.
 
 **Testing conventions** — see the Testing Conventions section below before writing any tests.
 
 ## Key Files for the Next Phase
 
-Phase 8 is complete — v1.0.0 released. Phase 9 (Ecosystem & Tooling) is next.
+Phase 8 is complete — v1.0.0 released. Wave 3 Reliability is complete. Phase 9 (Ecosystem & Tooling) is next.
 
 Phase 9 relevant areas (see `ROADMAP.md` for full spec):
 - `examples/` — end-to-end annotated examples (agentic memory, offline-first mobile, browser PWA)

@@ -91,7 +91,7 @@ let r2 = pq.execute(&[("tx", BindValue::TxCount(2)), ("entity", BindValue::Entit
 
 ```bash
 cargo run          # interactive Datalog REPL
-cargo test         # run 850 tests
+cargo test         # run 935 tests
 cargo run < demos/demo_recursive.txt   # recursive rules demo
 ```
 

@@ -1662,6 +1662,8 @@ When evaluating features, ask:
 - ✅ Phase 8.3d: Complete (April 2026) — Node.js `minigraf` on npm, 795 tests
 - ✅ Phase 8: Complete (May 2026) — v1.0.0
 - ✅ Wave 1 Performance: Complete (May 2026) — hash-join cluster + selective B+Tree lookup (#202, #203, #204, #208), 850 tests
+- ✅ Wave 2 Optimizer & Benchmarks: Complete (May 2026) — predicate push-down (#207, #206), cost-based not/or ordering (#205), SIMD crossover analysis (#229), 850 tests
+- ✅ Wave 3 Reliability: Complete (May 2026) — WAL fault injection, migration matrix, index corruption resilience, property-based testing, coverage gates, long-haul smoke, XTDB/Datomic compat (#209, #210, #212, #213, #214, #215, #216, #217, #219, #220, #221), 935 tests
 - 🎯 Phase 9: Ongoing (Ecosystem — integration examples, cookbook, GraphRAG/LangChain examples)
 
 **Note**: This is a hobby project. Timeline is flexible but realistic.
@@ -1681,7 +1683,7 @@ When evaluating features, ask:
 - ✅ 8.3c: C FFI (GitHub Releases) — v0.24.0
 - ✅ 8.3d: Node.js (npm) — v0.25.0
 
-**Next**: Phase 9 — Ecosystem & Tooling (post-release optimisation and benchmarking first)
+**Next**: Phase 9 — Ecosystem & Tooling (Wave 3 Reliability complete; moving to ecosystem, examples, and cookbook)
 
 **Key Decisions Made**:
 - ✅ Datalog query language (simpler, better for temporal)
@@ -1697,4 +1699,4 @@ See [GitHub Issues](https://github.com/project-minigraf/minigraf/issues) for spe
 
 ---
 
-**Last Updated**: Wave 1 Performance Complete (May 2026) — 850 tests passing, v1.0.0
+**Last Updated**: Wave 3 Reliability Complete (May 2026) — 935 tests passing, v1.0.0