Titus von Boxberg <titus(at)elbe-informatik(dot)de> writes:
> I got the following problem for which I could not find a solution by searching the archives:
> I have Tables Ta, Tb, Tc with primary keys as bigserials.
> Ta references Tb references Tc.
> Not all but most rows in Ta reference exactly one row in Tb.
Hm, your problem query has 11 table scans (not to mention a couple of
subplans) so you're oversimplifying here. Anyway, I think that increasing
join_collapse_limit and/or from_collapse_limit to at least 11 might help.
As-is, you're more or less at the mercy of whether your textual query
structure corresponds to a good join order.
regards, tom lane