The optimizer cost model usually needs 2 inputs, one is used to represent data distribution and the other one is used to represent the capacity of the hardware, like cpu/io let's call this one as system stats.
In Oracle database, the system stats can be gathered with dbms_stats.gather_system_stats [1] on the running hardware, In postgresql, the value is set on based on experience (user can change the value as well, but is should be hard to decide which values they should use). The pg way is not perfect in theory(In practice, it may be good enough or not). for example, HDD & SSD have different capacity regards to seq_scan_cost/random_page_cost, cpu cost may also different on different hardware as well.
I run into a paper [2] which did some research on dynamic gathering the values for xxx_cost, looks it is interesting. However it doesn't provide the code for others to do more research. before I dive into this, It would be great to hear some suggestion from experts.
so what do you think about this method and have we have some discussion about this before and the result?
