Beginner LevelPostgreSQL
What is PostgreSQL architecture and how do client backends connect via process fork model?
❓ Interview Prompt: Explain process-per-connection architecture, Postmaster daemon, client backend processes, shared_buffers, and connection pooling.
PostgreSQL utilizes a process-per-connection architecture rather than a multi-threaded execution model:
Core Architecture:
•
Postmaster Main Daemon: Master process listening on TCP port 5432.
•
Backend Process: When a client connects, Postmaster forks a dedicated OS backend process ('postgres') to handle that connection.
•
'shared_buffers': Shared RAM region accessible by all backend processes to cache data pages and indexes.
Code Implementation Example
sql
-- View active client backend processes and connected users
SELECT pid, usename, client_addr, state, query
FROM pg_stat_activity
WHERE state = 'active';💡Inspecting active PostgreSQL backend processes via pg_stat_activity.
🎯 Interview Key Takeaway
PostgreSQL uses a process-per-connection model where shared_buffers provides a centralized memory cache across backend processes.
#Architecture#Postmaster#shared_buffers#Process Model#Beginner
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