Module parquet_schema 

Parquet Schema Generation for SQL-on-FHIR

This module provides functionality for converting SQL-on-FHIR ViewDefinition outputs to Apache Parquet format with proper schema inference and data type mapping.

Overview

The parquet schema generator:

• Infers Arrow/Parquet schemas from FHIR data types
• Converts processed ViewDefinition rows to Arrow columnar format
• Handles collection columns as list types
• Maps FHIR primitive types to appropriate Arrow data types

Type Mappings

• FHIR String → Arrow UTF8
• FHIR Integer → Arrow Int32
• FHIR Decimal/Float → Arrow Float64
• FHIR Boolean → Arrow Boolean
• Collections → Arrow List types

Functions

create_arrow_schema

infer_arrow_type

process_to_arrow_arrays