> Regarding double buffering: I do not know how much double buffering would slow down operations. > It could also be possible to turn off kernel page cache on our DB server, to avoid double buffering. Although, we may still keep it in use.
I think you've misunderstood double buffering. The double buffering itself does not slow anything down. If the buffer is in shared buffers already then it does not need to look any further for it. Double buffering only becomes an issue when buffers existing 2 times in memory causes other useful buffers to appear 0 times.
