thrilltrack-explorer/docs/versioning/MIGRATION.md

Migration Guide

Migrating from JSONB entity_versions to relational version tables

Status

✅ Migration Complete - The relational versioning system is now active. This guide documents the migration for reference.

Overview

The old system stored versions in a single entity_versions table using JSONB:

• ❌ Not queryable
• ❌ No type safety
• ❌ Poor performance
• ❌ Complex RLS

The new system uses dedicated relational tables:

• ✅ Fully queryable
• ✅ Type-safe with foreign keys
• ✅ Indexed and performant
• ✅ Standard RLS policies

Migration Timeline

1. Phase 1: Create relational tables ✅ Complete
2. Phase 2: Enable triggers ✅ Complete
3. Phase 3: Dual-write period ✅ Complete
4. Phase 4: Backfill historical data ⏸️ Optional
5. Phase 5: Monitor 🔄 Ongoing
6. Phase 6: Deprecate JSONB table 📅 Future

Current State

• ✅ All new versions written to relational tables
• ✅ Triggers active on all entity tables
• ✅ Automated cleanup scheduled via pg_cron
• ⚠️ Old entity_versions table retained for backward compatibility
• ⚠️ src/lib/versioningHelpers.ts deprecated but not removed (scheduled for removal: 2025-12-01)

Migration Timeline

✅ Phase 1: New System Deployed (Completed)

• Relational version tables created (park_versions, ride_versions, etc.)
• Triggers enabled on all entity tables
• RLS policies active and tested
• Frontend integrated with new hooks
• Complete documentation suite created

🟡 Phase 2: Parallel Operation (Current - Days 1-30)

• Both old and new systems exist side-by-side
• New triggers create versions in relational tables
• Old JSONB table receives no new data
• Monitoring for issues and edge cases
• versioningHelpers.ts marked as deprecated

Action Items:

• Monitor version creation in new tables
• Verify no new inserts to old entity_versions table
• Search codebase for deprecated function usage
• Collect feedback from team

🔵 Phase 3: Archive Legacy Data (Day 30)

• Archive old entity_versions to entity_versions_archive
• Verify data integrity and counts match
• Keep archive for 60 more days as safety net
• Document archive location and access procedures

SQL Migration:

-- See supabase/migrations/*_archive_legacy_versions.sql
CREATE TABLE entity_versions_archive (LIKE entity_versions INCLUDING ALL);
INSERT INTO entity_versions_archive SELECT * FROM entity_versions;

🟢 Phase 4: Drop Legacy Tables (Day 90)

• Drop old entity_versions table
• Drop old RPC functions (create_entity_version, compare_versions, etc.)
• Remove src/lib/versioningHelpers.ts file
• Remove archive table (or retain indefinitely for audit)
• Update all documentation to remove references to old system

SQL Migration:

-- See supabase/migrations/*_drop_legacy_versions.sql
DROP TABLE entity_versions CASCADE;
DROP FUNCTION create_entity_version(...);

🚀 Phase 5: Optimization (Ongoing)

• Automated cleanup via pg_cron (monthly)
• Performance monitoring and index tuning
• Documentation updates based on usage patterns
• Version retention policy adjustments as needed

Backfill Script (Optional)

If you need to migrate historical JSONB versions to relational:

-- Backfill park versions
INSERT INTO park_versions (
  version_id, park_id, version_number, created_at, created_by,
  change_type, submission_id, is_current,
  name, slug, description, park_type, status,
  opening_date, opening_date_precision, closing_date, closing_date_precision,
  location_id, operator_id, property_owner_id,
  website_url, phone, email,
  banner_image_url, banner_image_id, card_image_url, card_image_id
)
SELECT
  ev.id, ev.entity_id, ev.version_number, ev.changed_at, ev.changed_by,
  ev.change_type, ev.submission_id, ev.is_current,
  ev.version_data->>'name',
  ev.version_data->>'slug',
  ev.version_data->>'description',
  ev.version_data->>'park_type',
  ev.version_data->>'status',
  (ev.version_data->>'opening_date')::date,
  ev.version_data->>'opening_date_precision',
  (ev.version_data->>'closing_date')::date,
  ev.version_data->>'closing_date_precision',
  (ev.version_data->>'location_id')::uuid,
  (ev.version_data->>'operator_id')::uuid,
  (ev.version_data->>'property_owner_id')::uuid,
  ev.version_data->>'website_url',
  ev.version_data->>'phone',
  ev.version_data->>'email',
  ev.version_data->>'banner_image_url',
  ev.version_data->>'banner_image_id',
  ev.version_data->>'card_image_url',
  ev.version_data->>'card_image_id'
FROM entity_versions ev
WHERE ev.entity_type = 'park'
ON CONFLICT DO NOTHING;

Cleanup (Future)

When ready to fully deprecate JSONB system:

-- 1. Verify all versions migrated
SELECT COUNT(*) FROM entity_versions; -- Should match relational tables

-- 2. Drop old table (IRREVERSIBLE)
DROP TABLE IF EXISTS entity_versions CASCADE;

-- 3. Remove deprecated helpers
-- Delete src/lib/versioningHelpers.ts

Rollback Plan

If issues arise, rollback steps:

1. Disable triggers on entity tables
2. Revert edge functions to use old JSONB system
3. Keep relational tables for future retry

Note: Not recommended - new system is production-ready.