Donald Dong <xdong@csumb.edu> writes:
> On Feb 16, 2019, at 6:44 PM, Tomas Vondra wrote:
>> I don't quite understand what is meant by "actual cost metric" and/or
>> how is that different from running EXPLAIN ANALYZE.
> Here is an example:
> Hash Join (cost=3.92..18545.70 rows=34 width=32) (actual cost=3.92..18500 time=209.820..1168.831 rows=47 loops=3)
> Now we have the actual time. Time can have a high variance (a change
> in system load, or just noises), but I think the actual cost would be
> less likely to change due to external factors.
I'm with Tomas: you have not explained what you think those
numbers mean.
regards, tom lane