Week 03 Lecture (22)

Exercise 3: PostgreSQL Buffer Pool

Consider an initally empty buffer pool with only 3 slots.

Show the state of the pool after each of the following:

Req R0, Req S0, Rel S0, Req S1, Rel S1, Req S2,
Rel S2, Rel R0, Req R1, Req S0, Rel S0, Req S1,
Rel S1, Req S2, Rel S2, Rel R1, Req R2, Req S0,
Rel S0, Req S1, Rel S1, Req S2, Rel S2, Rel R2

Treat BufferDesc entries as

(tag, usage_count, refcount, freeNext)

Assume freeList and nextVictim global variables.