Bricklen Anderson reported a problem with explains that were using parallel processing.
TL;DR: in case of parallel plans make “inclusive" and “exclusive" be wall-clock times, and not “how much time CPU did spend on it".
The problem can be seen in here:
and in here:
You can see, in first one, that time in partial aggregate step (#3) is actually longer than total time of the query. This is/was because of parallel processing.
Similarly in second plan, in step 16 times are totally abstract.
Based on the problem I released new version of Pg::Explain library, which solves this problem (and also fixes anonymization of elements in parallel plans).
With this new version, we have new explains: