4 ms·
This seems like something that should be measured at startup?
by topbanana 9y ago
This seems like something that should be measured at startup?
- jeltz 9y agoSadly that is not (at least easily) possible because random_page_cost vs. sequential_page_cost is not just about the IO system but about all factors which can affect the cost of reading pages randomly vs reading pages sequentially. E.g. how often PostgreSQL's tables are in the file cache. So how much RAM your machine has available for PostgreSQL and your access patterns matter too. Also I imagine the some expensive SAN solutions would be pretty tricky to measure given how smart they try to be with caching and moving between different kinds of disks.