Re: Introducing floating point cast into filter drastically changes row estimate - Mailing list pgsql-bugs

From Merlin Moncure
Subject Re: Introducing floating point cast into filter drastically changes row estimate
Date
Msg-id CAHyXU0xBrNk1PNQOK8o1suwMZtXweJMSvgbb6hUKdNwapK6AaQ@mail.gmail.com
Whole thread Raw
In response to Introducing floating point cast into filter drastically changes row estimate  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-bugs
On Wed, Oct 24, 2012 at 10:06 AM, Merlin Moncure <mmoncure@gmail.com> wrote:
> I was chasing down a query that ran fine in 8.1 but had an near
> infinite runtime in 9.2.  It turned out to be from a bad filter
> estimate that is surprisingly simple to reproduce:

Testing some more it turns out that this isn't really a bug -- it's
just a general property of expression based filters: the planner
assumes they are very selective when in this case they are not.

merlin

pgsql-bugs by date:

Previous
From: Greg Hazel
Date:
Subject: Re: BUG #7620: array_to_json doesn't support heterogeneous arrays
Next
From: Greg Hazel
Date:
Subject: Re: BUG #7620: array_to_json doesn't support heterogeneous arrays