PostgreSQL Enterprise & Performance
5-8 Years (Senior)
Hard
Production Scenario
How does `EXPLAIN (ANALYZE, BUFFERS)` reveal Shared Hit vs Shared Read disk IO bottlenecks?
Real-World Scenario / Incident Description
Determining whether a slow query is CPU-bound or waiting for disk pages to be loaded into PostgreSQL shared buffers.
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Updated 1 month ago
Analyzing BUFFERS Metrics
EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM accounts WHERE balance > 50000;
shared hit=5000: 5,000 data blocks were read directly from RAM (Shared Buffers cache) with zero disk latency.shared read=8000: 8,000 blocks had to be fetched from physical disk or OS filesystem cache.
Related Concepts:
#EXPLAIN BUFFERS
#Shared Buffers
#IO Performance
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