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HeliosDB-Lite Feature Analysis Documentation Index

HeliosDB-Lite Feature Analysis Documentation Index

This index provides quick navigation to comprehensive feature analysis reports generated for UPDATE, DELETE, TRUNCATE, and CTE support in HeliosDB-Lite v2.4.0-beta.

Documents Overview

1. Quick Reference Summary

File: docs/implementation/UPDATE_DELETE_TRUNCATE_CTE_SUMMARY.md Length: ~400 lines Best for: Quick lookup, status checks, priority planning

Contents:

  • Feature implementation matrix (visual table)
  • Implementation quality breakdown for each feature
  • Critical issue explanation (transaction bypass)
  • Execution path comparison (current vs correct)
  • Priority fix list with effort estimates
  • Files to change for each fix
  • Testing impact assessment

Read this first if you want: Quick understanding of what works, what doesn’t, and what to fix

2. Detailed Technical Analysis

File: docs/implementation/UPDATE_DELETE_TRUNCATE_CTE_FEATURE_ANALYSIS.md Length: ~500 lines Best for: Deep dive, implementation planning, code review

Contents:

Section 1: UPDATE Statement

  • Current implementation status (WORKING with limitations)
  • What’s working (basic updates, WHERE clauses, parameterized queries)
  • What’s NOT working (transaction buffering, UPDATE…FROM, column references)
  • Code locations with line numbers
  • Critical issue analysis
  • Limitations and issues

Section 2: DELETE Statement

  • Current implementation status (WORKING with limitations)
  • What’s working (single/multiple row delete, WHERE clauses, parameterized queries)
  • What’s NOT working (transaction buffering, DELETE…USING, cascading deletes)
  • Code locations with line numbers
  • Limitations and issues

Section 3: TRUNCATE Statement

  • Current implementation status (WORKING)
  • What’s working (removes all rows, atomic operation, fast)
  • What’s NOT working (WHERE clause, CASCADE option, multiple table truncate)
  • Code locations with line numbers
  • Limitations and issues

Section 4: CTE (Common Table Expressions)

  • Current implementation status (NOT IMPLEMENTED)
  • Complete feature absence (no partial implementation)
  • Error location and behavior
  • What would be needed to implement
  • Complexity assessment (2-3 weeks for basic implementation)

Summary Section

  • Feature status table
  • Code quality assessment
  • Recommendations (short/medium/long term)
  • Files to review/modify

Read this when you: Need to implement fixes or understand the codebase

Key Findings Summary

Feature Status at a Glance

Feature        Status              Critical Issue
─────────────────────────────────────────────────
UPDATE         Working             Transaction bypass
DELETE         Working             Transaction bypass
TRUNCATE       Working             Transaction bypass
CTE (WITH)     Not Implemented     Completely absent

Critical Issue: Transaction Bypass

All three DML operations (UPDATE, DELETE, TRUNCATE) bypass transaction write sets when executed in explicit transactions. This is a documented limitation but represents broken ACID compliance.

Example of the problem:

db.begin()?;
db.execute("UPDATE users SET age = 31 WHERE id = 1")?;
db.rollback()?;  // Even after rollback, UPDATE persists!

Root cause: Lines in src/lib.rs:382-388 use executor which doesn’t know about the transaction context.

Fix: Move UPDATE/DELETE/TRUNCATE handling from execute_internal() into execute_in_transaction() (estimated 2-3 days)

CTE Feature

Completely unimplemented. Any query with a WITH clause returns an error immediately. Implementation would take 2-3 weeks for basic (non-recursive) support.

How to Use These Documents

Scenario 1: “I want to fix the transaction bypass issue”

  1. Read: SUMMARY (Priority 1 section)
  2. Read: ANALYSIS (What’s NOT Working sections)
  3. Review: Code locations in lib.rs lines 232-390
  4. Use: Summary’s “Files to Change” section

Scenario 2: “I need to implement CTE support”

  1. Read: SUMMARY (CTE section)
  2. Read: ANALYSIS (CTE section with implementation requirements)
  3. Review: Code location planner.rs:156-159
  4. Plan: Use the “What Would Be Needed” checklist

Scenario 3: “I’m auditing the SQL implementation”

  1. Read: SUMMARY (entire document for overview)
  2. Read: ANALYSIS (detailed sections for each feature)
  3. Check: Test coverage information in both documents
  4. Reference: Code locations provided throughout

Scenario 4: “I need to report on SQL feature readiness”

  1. Read: SUMMARY (Feature Status Matrix section)
  2. Use: Summary Table and Conclusion
  3. Reference: Priority Fix List for roadmap
  4. Share: Summary document with non-technical stakeholders

Code Locations Reference

UPDATE Implementation

ComponentFileLinesPurpose
SQL Parsersrc/sql/planner.rs1062-1104Parse UPDATE to LogicalPlan
Logical Plansrc/sql/logical_plan.rs146-154Define Update variant
Executorsrc/lib.rs667-723Execute UPDATE (without transaction)
Transaction Wrappersrc/lib.rs232-390Handle transaction (BROKEN)

DELETE Implementation

ComponentFileLinesPurpose
SQL Parsersrc/sql/planner.rs1107-1129Parse DELETE to LogicalPlan
Logical Plansrc/sql/logical_plan.rs156-162Define Delete variant
Executorsrc/lib.rs724-774Execute DELETE (without transaction)
Transaction Wrappersrc/lib.rs232-390Handle transaction (BROKEN)

TRUNCATE Implementation

ComponentFileLinesPurpose
SQL Parsersrc/sql/planner.rs75-85Parse TRUNCATE to LogicalPlan
Logical Plansrc/sql/logical_plan.rs140-144Define Truncate variant
Executorsrc/lib.rs792-820Execute TRUNCATE (without transaction)
Transaction Wrappersrc/lib.rs232-390Handle transaction (BROKEN)

CTE (WITH) Implementation

ComponentFileLinesPurpose
Feature Gatesrc/sql/planner.rs156-159Returns “not yet supported” error
Logical Plansrc/sql/logical_plan.rsN/ANo variant defined yet
Executorsrc/sql/executor/mod.rsN/ANo handling yet

Test Coverage Analysis

UPDATE/DELETE Tests

Status: 100% coverage for basic operations

Test Location: tests/crud_tests.rs

Tests Present:

  • test_update_single_row()
  • test_update_multiple_rows()
  • test_update_all_rows()
  • test_update_multiple_columns()
  • test_update_no_matching_rows()
  • test_update_with_complex_where()
  • test_delete_single_row()
  • test_delete_multiple_rows()
  • test_delete_all_rows()
  • test_delete_no_matching_rows()
  • test_delete_with_complex_where()
  • test_delete_and_reinsert()

Tests Missing:

  • UPDATE/DELETE in explicit transactions
  • TRUNCATE operations
  • UPDATE with column references
  • UPDATE…FROM clause

TRUNCATE Tests

Status: No dedicated tests found

Need to Add:

  • test_truncate_removes_all_rows()
  • test_truncate_returns_row_count()
  • test_truncate_non_existent_table()

CTE Tests

Status: Not applicable (feature not implemented)

Recommendations by Timeline

v2.5.0 (Next Release) - CRITICAL

  1. Fix UPDATE/DELETE/TRUNCATE transaction bypass (2-3 days)

    • Move implementations into execute_in_transaction()
    • Mirror INSERT pattern
    • Add explicit transaction tests
    • Impact: Restore ACID compliance

  2. Add TRUNCATE tests (1 day)

    • Basic TRUNCATE test
    • Non-existent table handling
    • Row count verification

v2.6.0 (Minor Release) - IMPORTANT

  1. Enable column references in UPDATE (3 days)

    • Support UPDATE users SET age = age + 1
    • Common SQL pattern

  2. Expand transaction tests (2 days)

    • More explicit transaction coverage
    • Nested transaction tests
    • Rollback scenarios

v3.0.0 (Major Release) - USEFUL

  1. Implement basic CTE support (2-3 weeks)

    • Non-recursive CTEs only
    • Single CTE support
    • Comprehensive test suite

  2. Add UPDATE…FROM clause (1 week)

    • Enable table joins in UPDATE
    • Expand UPDATE capabilities

  3. Performance optimization (2 weeks)

    • Index-based seeks for UPDATE/DELETE
    • 10-100x performance improvement

v3.1.0+ (Future Releases) - NICE TO HAVE

  1. Recursive CTE support
  2. RETURNING clause for UPDATE/DELETE
  3. Foreign key cascading deletes
  4. Window functions for CTEs

If you’re a developer:

  • Start with SUMMARY for quick orientation
  • Then read ANALYSIS for detailed requirements
  • Reference Code Locations Reference section while coding
  • Use Recommendations by Timeline for planning

If you’re a manager/lead:

  • Read Feature Status at a Glance section
  • Review Recommendations by Timeline for roadmap
  • Check Test Coverage Analysis for quality metrics
  • Reference Critical Issue section for prioritization

If you’re doing code review:

  • Use Code Locations Reference to find relevant code
  • Check What’s NOT Working sections to understand limitations
  • Review Test Coverage Analysis to verify testing

If you’re troubleshooting:

  • Check What’s NOT Working sections first
  • Read Limitations & Issues sections
  • Look at Critical Issue: Transaction Bypass if using explicit transactions

Document Metadata

Created: 2025-11-29 Analysis Tool: Anthropic Claude Code Database Version: HeliosDB-Lite v2.4.0-beta Test Pass Rate: 95.1% (527/554 tests)

Report Covers:

  • UPDATE statement support
  • DELETE statement support
  • TRUNCATE statement support
  • CTE (WITH clause) support
  • Transaction buffering analysis
  • Code locations and references
  • Test coverage assessment
  • Implementation roadmap

See Also

  • README.md - Project overview and quick start
  • KNOWN_ISSUES-v2.4.0-beta.md - Known issues and limitations
  • docs/implementation/ - Other implementation reports
  • docs/guides/developer/FEATURE_DEVELOPMENT_PROTOCOL.md - Development guidelines

Questions or Feedback?

These analysis documents are maintained as part of the HeliosDB-Lite documentation suite. For questions or corrections, refer to the project’s issue tracker or documentation guidelines.

Document Files:

  • Main analysis: docs/implementation/UPDATE_DELETE_TRUNCATE_CTE_FEATURE_ANALYSIS.md
  • Quick reference: docs/implementation/UPDATE_DELETE_TRUNCATE_CTE_SUMMARY.md
  • This index: FEATURE_ANALYSIS_INDEX.md