Architecture

PostgreSQL Architecture PostgreSQL follows a client-server architecture with several key components:

Core Components

• Postmaster: The main PostgreSQL server process that manages connections and spawns backend processes

• Backend Processes: Individual processes that handle client connections and execute queries

• Shared Memory: Used for caching data pages, transaction logs, and inter-process communication

• WAL (Write-Ahead Logging): Ensures data durability and enables point-in-time recovery

Process Architecture

• Connection Process: Handles client authentication and connection management

• Background Processes: Autovacuum, checkpointer, WAL writer, and statistics collector

• Utility Processes: Background writer, archiver, and replication processes

Storage Architecture

• Data Directory: Contains all database files, configuration files, and logs

• Tablespaces: Allow storing database objects in different file system locations

• Pages: Fixed-size blocks (8KB by default) that store table and index data

• MVCC: Multi-Version Concurrency Control for transaction isolation