[Solved] A PostgreSQL server has effective_cache_size set too low. What problem might this cause? — Ans: PostgreSQL may underestimate available cache and choose inefficient query plans | PostgreSQL

PostgreSQL - Performance Tuning

A PostgreSQL server has effective_cache_size set too low. What problem might this cause?

APostgreSQL will allocate too much memory for sorting operations

BThe server will crash due to memory exhaustion

CPostgreSQL may underestimate available cache and choose inefficient query plans

DConnections will be refused due to low cache size

Step-by-Step Solution

Solution:

Step 1: Understand effective_cache_size role
This setting helps PostgreSQL estimate how much OS cache is available for data pages.
Step 2: Consequence of low effective_cache_size
If set too low, PostgreSQL thinks less cache is available, so it may avoid index scans or other efficient plans, choosing slower ones.
Final Answer:
PostgreSQL may underestimate available cache and choose inefficient query plans -> Option C
Quick Check:
Low effective_cache_size = conservative query plans [OK]

Quick Trick: Low effective_cache_size causes conservative, slower plans [OK]

Common Mistakes:

Master "Performance Tuning" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

A PostgreSQL server has effective_cache_size set too low. What problem might this cause?