On Wed, 2025-04-23 at 00:21 -0500, Igor Korot wrote: > On the page > https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-SEQ-PAGE-COST > > it is only given the default value of this parameter. > > No min/max values are provided.. > > The same can be sad about > https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-RANDOM-PAGE-COST
Sad. But you can interpret it as "there is no maximum". The actual maximum is DBL_MAX, the biggest double precision value that your system can handle, and may depend on your architecture. > However, this page > https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-EFFECTIVE-IO-CONCURRENCY > describes both default and mn/max, however t s says: > > [quote] > The default is 1 on supported systems, otherwise 0 > [/quote]] > > No explanation of what is "supported system" is given... > > And the same can be said about > https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAINTENANCE-IO-CONCURRENCY. According to the source, it is "systems that have posix_fadvise()". We could document that, but I don't know if it would help many people. I am not sure how easy and feasible it is to research which versions of which operating systems qualify. Yours, Laurenz Albe
