Re: Costs of Heap Fetches in Postgres 13

2020-07-30 Thread David Rowley
On Fri, 31 Jul 2020 at 05:21, wrote: > does the planner do estimates about heap fetches on index only scans and > takes them into account? > At least in Pg 13? If so, is it possible to lower those costs? > random_page_costs seems not to have any influence. > Looks like they cause bad planner de

Costs of Heap Fetches in Postgres 13

2020-07-30 Thread Jens . Wilke
Hi, does the planner do estimates about heap fetches on index only scans and takes them into account? At least in Pg 13? If so, is it possible to lower those costs? random_page_costs seems not to have any influence. Looks like they cause bad planner decisions. Tuning Vacuum is not an option ;)