TLDR Tech / DevOps
The real cost of random I/O
Experiments show random I/O on SSDs is ~25–35× slower than sequential reads, far above PostgreSQL's default random_page_cost = 4.0, meaning the default often underestimates true cost. Still, lowering it can make sense depending on caching and workload, so changes should be based on real performance data, not just SSD assumptions.
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