Skip to content
HeliosDB HeliosDB Nano

HeliosDB Nano Feature Analysis Documentation Index

HeliosDB Nano Feature Analysis Documentation Index

This index provides quick navigation to comprehensive feature analysis reports generated for UPDATE, DELETE, TRUNCATE, and CTE support in HeliosDB Nano 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 Nano 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 Nano 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