Research Initiatives Tracking

Purpose: Track progress on research initiatives identified post-Phase 6 completion Related: See RESEARCH_INITIATIVES.md for detailed plans Last Updated: 2025-11-11

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Active Initiatives

None Currently Active

All initiatives are in Planning phase awaiting approval to begin.

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Initiative Status Dashboard

Initiative	Status	Phase	Progress	Started	ETA
SIMD Edge Search	🟡 Planning	0/4	0%	-	2-4 weeks
Hybrid Storage	🟡 Planning	0/4	0%	-	4-6 weeks
DAT/DAWG Hybrid	🟡 Planning	0/5	0%	-	8-12 weeks

Status Legend:

• 🟡 Planning: Not started, awaiting approval
• 🔵 Active: Currently in progress
• 🟢 Complete: Finished successfully
• 🔴 Abandoned: Discontinued (see conclusion for rationale)
• ⏸️ Paused: Temporarily suspended

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SIMD Edge Search

Metadata

• Initiative ID: RES-001
• Priority: Medium
• Estimated Effort: 2-4 weeks
• Risk Level: Low-Medium
• Status: 🟡 Planning
• Branch: (none yet)

Phases

Phase 1: Analysis (Week 1)

Status: Not started Goals:

• [ ] Profile current DynamicDawg for edge lookup hotspots
• [ ] Measure edge count distribution in typical dictionaries
• [ ] Analyze flamegraph to determine if edge search is bottleneck (≥5% threshold)

Decision Point: If edge search < 5% of total time → ABANDON

Phase 2: Microbenchmark (Week 2)

Status: Not started Depends on: Phase 1 success Goals:

• [ ] Extract SIMD logic from OptimizedDawg
• [ ] Create benches/edge_search_comparison.rs
• [ ] Benchmark at edge counts: 2, 4, 8, 16, 32, 64
• [ ] Test cache sensitivity (warm vs cold)
• [ ] Determine breakeven point

Decision Point: If SIMD slower or marginal (< 5% improvement) → ABANDON

Phase 3: Integration (Week 3)

Status: Not started Depends on: Phase 2 success Goals:

• [ ] Implement SIMD edge search in DynamicDawg
• [ ] Add simd-edge-search feature flag
• [ ] Ensure all tests pass with SIMD enabled

Phase 4: Validation (Week 4)

Status: Not started Depends on: Phase 3 success Goals:

• [ ] Run end-to-end benchmarks on corpus workloads
• [ ] Compare baseline vs SIMD using Criterion
• [ ] Profile with flamegraph to verify optimization

Decision Point:

• ≥10% speedup → MERGE and enable by default
• 5-10% speedup → MERGE but keep as opt-in
• <5% speedup → ABANDON

Artifacts

• Design doc: (pending)
• Feature branch: (pending)
• Benchmarks: (pending)
• Flamegraphs: (pending)
• Conclusion: (pending)

Notes

• Requires AVX2-capable CPU (✅ Available: Xeon E5-2699 v3)
• OptimizedDawg SIMD code preserved for reference
• Early exit criteria at each phase minimize wasted effort

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Hybrid Storage

Metadata

• Initiative ID: RES-002
• Priority: Low
• Estimated Effort: 4-6 weeks
• Risk Level: Medium-High
• Status: 🟡 Planning
• Branch: (none yet)

Phases

Phase 1: Analysis (Weeks 1-2)

Status: Not started Goals:

• [ ] Memory profiling of current DynamicDawg using Valgrind massif
• [ ] Component breakdown: node overhead, Vec capacity, alignment padding
• [ ] Estimate theoretical savings from arena storage

Decision Point: If potential savings < 20% → ABANDON

Phase 2: Prototype (Weeks 3-4)

Status: Not started Depends on: Phase 1 success Goals:

• [ ] Implement hybrid storage in feature branch
• [ ] Create DynamicDawgImmutable type
• [ ] Implement conversion from DynamicDawg
• [ ] Verify correctness: all tests pass

Phase 3: Benchmarking (Week 5)

Status: Not started Depends on: Phase 2 success Goals:

• [ ] Memory benchmarks
• [ ] Query performance benchmarks
• [ ] Construction overhead benchmarks

Decision Point: If <20% memory reduction OR >5% query regression → ABANDON

Phase 4: API Design (Week 6)

Status: Not started Depends on: Phase 3 success Goals:

• [ ] Design user-facing API (separate type vs mode flag vs type state)
• [ ] Document API with examples
• [ ] Integration testing with transducers

Artifacts

• Design doc: (pending)
• Feature branch: (pending)
• Memory profiles: (pending)
• Benchmarks: (pending)
• API documentation: (pending)
• Conclusion: (pending)

Notes

• Higher complexity due to dual storage modes
• Maintenance burden: two code paths to test
• May increase codebase complexity without sufficient benefit
• Consider API usability carefully

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DAT/DAWG Hybrid

Metadata

• Initiative ID: RES-003
• Priority: High (novel contribution)
• Estimated Effort: 8-12 weeks
• Risk Level: High
• Status: 🟡 Planning
• Branch: (none yet)

Phases

Phase 1: Literature Review & Design (Weeks 1-3)

Status: Not started Goals:

• [ ] Literature survey: DAT papers (Aoe 1989, Yata 2007, etc.)
• [ ] Literature survey: DAWG papers (Crochemore 1985, etc.)
• [ ] Search for existing DAT+DAWG combinations
• [ ] Create comprehensive design document (30+ pages)
• [ ] Complexity analysis: theoretical bounds

Deliverable: docs/research/DAT_DAWG_HYBRID_DESIGN.md

Decision Point: If design shows fundamental flaw or prior art exists → ABANDON

Phase 2: Prototype Implementation (Weeks 4-7)

Status: Not started Depends on: Phase 1 success Goals:

• [ ] Implement core data structure (DatDawgHybrid)
• [ ] Implement construction algorithm
• [ ] Implement query algorithm
• [ ] Basic functionality working

Phase 3: Correctness Validation (Week 8)

Status: Not started Depends on: Phase 2 success Goals:

• [ ] Comprehensive unit tests
• [ ] Property-based tests
• [ ] Fuzzing with random dictionaries
• [ ] Equivalence testing vs reference DAWG

Phase 4: Performance Benchmarking (Weeks 9-10)

Status: Not started Depends on: Phase 3 success Goals:

• [ ] Construction benchmarks vs all backends
• [ ] Query benchmarks vs all backends
• [ ] Memory measurements vs all backends
• [ ] Flamegraph analysis

Decision Point: If performance worse than DynamicDawg → ANALYZE for optimization opportunities

Phase 5: Optimization (Weeks 11-12)

Status: Not started Depends on: Phase 4 results Goals:

• [ ] Optimize hot paths identified in flamegraphs
• [ ] Cache-friendly data layout
• [ ] SIMD opportunities (if applicable)
• [ ] Re-benchmark after optimizations

Success Criteria:

• Space: Within 2× of DynamicDawg
• Speed: Within 2× of DoubleArrayTrie
• Construction: Better than DoubleArrayTrie

Artifacts

• Literature review: docs/research/DAT_DAWG_HYBRID/references/ (pending)
• Design doc: docs/research/DAT_DAWG_HYBRID/DESIGN.md (pending)
• Feature branch: (pending)
• Prototype code: (pending)
• Benchmarks: (pending)
• Flamegraphs: (pending)
• Paper draft: (if successful - pending)
• Conclusion: (pending)

Notes

• Most ambitious initiative (novel data structure)
• Success probability: 40-60%
• Potential for academic publication if successful
• Requires deep expertise in both DAT and DAWG algorithms
• MP DAT is different (uses TAIL array, not suffix sharing in DAT part)

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Completed Initiatives

None Yet

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Abandoned Initiatives

None Yet

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Decision Log

2025-11-11: Initiatives Identified

Context: OptimizedDawg deprecation analysis revealed potential optimization opportunities Decision: Document three research initiatives for future work Rationale:

• Phase 6 now complete (100% feature parity)
• OptimizedDawg deprecated (reduced maintenance burden)
• Time to explore advanced optimizations Status: All initiatives in Planning phase

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Methodology Standards

All research initiatives must follow the scientific method:

1. Hypothesis Formation

• Clear, testable hypothesis with null hypothesis (H₀)
• Defined success criteria (quantitative)
• Alternative outcomes considered

2. Methodology Design

• Phased approach with early exit criteria
• Decision points based on empirical data
• Controls and baselines defined

3. Data Collection

• Benchmarking with Criterion (statistical rigor)
• Profiling with flamegraph + perf
• Memory measurement with Valgrind/heaptrack
• Multiple corpora for validation

4. Analysis

• Statistical significance testing
• Comparison against baseline
• Identify bottlenecks and optimization opportunities

5. Conclusion

• Accept or reject hypothesis based on data
• Document findings comprehensively
• Preserve results for future reference

6. Documentation

Every initiative must produce:

• Design document (before implementation)
• Benchmark results (data-driven decisions)
• Flamegraphs (performance analysis)
• Conclusion document (final analysis)
• Code artifacts (if successful)

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Resource Requirements

Tools Available

• ✅ Criterion (statistical benchmarking)
• ✅ flamegraph + perf (profiling)
• ✅ Valgrind massif (memory profiling)
• ⚠️ heaptrack (install if needed)

Corpora Available

• ✅ big.txt (Norvig corpus, 1M+ words)
• ✅ holbrook.dat (spelling errors)
• ✅ /usr/share/dict/words (system dictionary)

Hardware

• ✅ Xeon E5-2699 v3 (36 cores, AVX2 support)
• ✅ 252 GB RAM (sufficient for large-scale tests)
• ✅ 4TB NVMe SSD (fast I/O)

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Communication Guidelines

Starting an Initiative

1. Review detailed plan in RESEARCH_INITIATIVES.md
2. Create design document in docs/research/[initiative-name]/
3. Update this file: set Status to 🔵 Active
4. Create feature branch: research/[initiative-name]
5. Update tracking as each phase completes

Completing a Phase

1. Check off completed goals in phase section
2. Document artifacts created
3. Update progress percentage
4. If decision point reached: document decision and rationale

Abandoning an Initiative

1. Update Status to 🔴 Abandoned
2. Document reason in Notes section
3. Create conclusion document explaining decision
4. Archive artifacts for future reference

Completing an Initiative

1. Update Status to 🟢 Complete
2. Move to "Completed Initiatives" section
3. Document final outcomes
4. Update main codebase if successful
5. Update CHANGELOG.md

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Next Steps

Immediate: All initiatives documented and ready for approval

To start any initiative:

1. Review detailed plan in RESEARCH_INITIATIVES.md
2. Confirm time commitment available
3. Create design document
4. Begin Phase 1

Recommended starting order:

• Quick wins: Start with SIMD Edge Search (2-4 weeks)
• Novel contribution: Start with DAT/DAWG Hybrid (8-12 weeks)
• Practical improvement: Start with SIMD, skip others unless successful

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Maintainer: (project maintainer) Last Updated: 2025-11-11 Next Review: After first initiative completion