The statistics collector documentation says:
“The parameter stats_start_collector must be set to true for the statistics collector to be launched at all. This is the default and recommended setting, but it may be turned off if you have no interest in statistics and want to squeeze out every last drop of overhead. (The savings is likely to be small, however.) Note that this option cannot be changed while the server is running. “
Is there a way to quantify what ‘likely to be small’ is?