On 2/17/19 3:40 AM, David Fetter wrote: > On Sat, Feb 16, 2019 at 03:10:44PM -0800, Donald Dong wrote: >> Hi, >> >> When explaining a query, I think knowing the actual rows and pages >> in addition to the operation type (e.g seqscan) would be enough to >> calculate the actual cost. The actual cost metric could be useful >> when we want to look into how off is the planner's estimation, and >> the correlation between time and cost. Would it be a feature worth >> considering? > > As someone not volunteering to do any of the work, I think it'd be a > nice thing to have. How large an effort would you guess it would be > to build a proof of concept? >
I don't quite understand what is meant by "actual cost metric" and/or how is that different from running EXPLAIN ANALYZE. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
