H2 Database Support Implementation#

#Overview

This document outlines the implementation of H2 database support for the Firmiana Matrix Chat Server, providing an in-memory or file-based database alternative to MongoDB for development and testing.

#Objectives

• Add H2 as an alternative database backend alongside MongoDB
• Maintain compatibility with existing MongoDB implementations
• Provide configuration options to switch between database backends
• Support both in-memory and persistent H2 modes

#Scope

• Add H2 JDBC driver dependency
• Configure Micronaut Data for H2 support
• Create database schema and initialization
• Update repository layer to support both databases
• Add configuration properties for database selection

#Implementation Details

#Dependencies

• h2: H2 database engine
• Micronaut Data JDBC: ORM support
• r2dbc-h2: R2DBC driver for reactive access

#Configuration

• Add database.type property (mongodb or h2)
• Add h2.mode property (memory or file)
• Add h2.path property for file-based storage
• Conditional bean creation based on database type

#Database Schema

• Create schema for all entities
• Define indexes for performance
• Set up relationships and constraints

#Benefits

• Fast in-memory database for testing
• Persistent file-based option for development
• No external database server required
• Excellent for CI/CD pipelines
• Web console for database inspection

#Timeline

• Phase 1: Add dependencies and configuration
• Phase 2: Create database schema
• Phase 3: Update repositories
• Phase 4: Testing and validation