On 3rd of April 2019, Tomas Vondra committed patch:
Add SETTINGS option to EXPLAIN, to print modified settings. Query planning is affected by a number of configuration options, and it may be crucial to know which of those options were set to non-default values. With this patch you can say EXPLAIN (SETTINGS ON) to include that information in the query plan. Only options affecting planning, with values different from the built-in default are printed. This patch also adds auto_explain.log_settings option, providing the same capability in auto_explain module. Author: Tomas Vondra Discussion: https://postgr.es/m/e1791b4c-df9c-be02-edc5-7c8874944be0@2ndquadrant.com