Horton

Re: BUG #15336: Wrong cursor's bacward fetch results in select with ALL(subquery)

Andrew Gierth <andrew@tao11.riddles.org.uk>

View thread View on postgr.es
From: Andrew Gierth <andrew@tao11.riddles.org.uk>
To: pgsql-bugs@lists.postgresql.org
Cc: v.g.baranoff@gmail.com
Date: 2018-08-17T13:56:46Z
Lists: pgsql-bugs

Attachments

>>>>> "Andrew" == Andrew Gierth <andrew@tao11.riddles.org.uk> writes:

 Andrew> I'm guessing that locally saving/restoring the scan direction
 Andrew> in ExecSubPlan is going to be the best option; it seems to fix
 Andrew> the problem, I'll post a patch in a bit.

It turns out to be also necessary to do this in ExecSetParamPlan, though
I couldn't find a way to make a stable regression test for that - my
manual tests were based on putting a subselect inside a volatile
construct like CASE WHEN random() < x THEN.

Patch attached.

-- 
Andrew (irc:RhodiumToad)

Commits

  1. Set scan direction appropriately for SubPlans (bug #15336)

  2. Get rid of the separate EState for subplans, and just let them share the