This chapter covers how PostgreSQL interacts with RAM. We will contrast PostgreSQL's shared_buffers with the operating system page cache (double buffering). Students will learn how work_mem dictates the performance of sorts and hash tables, and how the clock-sweep algorithm handles buffer eviction.

Outside Reading

• Official Docs: Chapter 15: Managing Disk Space. (Focus on the Visibility Map and Free Space Map).
• GitHub Source: src/backend/storage/buffer/bufmgr.c. Trace the StrategyGetBuffer() function. Read the core team's comments explaining the "Clock Sweep" cache eviction algorithm.