# Changelog

All notable changes to the OMOP Data Pipeline 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).

## [0.1.0] - 2024-01-XX

### Added
- Initial release of OMOP CDM 5.4 Data Pipeline
- Complete OMOP CDM 5.4 schema implementation (30+ tables)
- Staging schema for raw data ingestion
- Audit schema for ETL tracking and data quality metrics
- Extractor component for batch and incremental extraction
- Concept Mapper with LRU caching and multi-level mapping strategy
- Transformer for all major OMOP tables (PERSON, VISIT_OCCURRENCE, CONDITION_OCCURRENCE, etc.)
- Validator with comprehensive data quality checks
- Loader with bulk insert and UPSERT capabilities
- Orchestrator for coordinating complete ETL flow
- Parallel processing with ThreadPoolExecutor
- Error Handler with retry logic, circuit breaker, and checkpoint/resume
- CLI interface with comprehensive commands
- Vocabulary Loader for OMOP vocabularies
- Configuration management with YAML and environment variables
- Comprehensive logging with file rotation
- Database connection pooling with retry logic
- Pydantic models for all OMOP tables
- PostgreSQL sequences for ID generation

### Features
- Automated concept mapping with fallback strategies
- Batch processing with configurable batch sizes
- Multi-threaded parallel processing
- Transaction management with automatic rollback
- Foreign key validation before loading
- Date validation and parsing
- Referential integrity checks
- OMOP compliance validation
- Unmapped code tracking
- Execution statistics and audit trail
- Progress bars for long-running operations
- Verbose logging mode

### Documentation
- README with quick start guide
- User guide with detailed instructions
- Architecture documentation
- Transformation rules documentation
- API documentation in code
- Configuration examples

### Requirements
- Python 3.12+
- PostgreSQL 16.11+
- SQLAlchemy 2.0+
- Pydantic 2.5+
- Click 8.1+
- Other dependencies in requirements.txt

## [Unreleased]

### Planned
- Property-based tests with Hypothesis
- Integration tests for complete ETL flow
- Performance benchmarking suite
- Docker containerization
- CI/CD pipeline
- Data Quality Dashboard integration
- Additional source data formats (HL7, FHIR)
- Incremental ETL mode
- Data lineage tracking
- Web-based monitoring dashboard
- REST API for programmatic access