The real cost of random I/O

The random_page_cost was introduced ~25 years ago and has been set to 4.0 by default. Recent experiments show that the actual cost of reading a random page may be much higher than this default value, especially on fast SSD storage. Lowering the random_page_cost value may not always be the best approach, as factors like cache efficiency, prefetching, and query isolation need to be considered for optimal performance.