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From: Adam Brusselback <[email protected]>
To: Tom Lane <[email protected]>
Cc: [email protected]
Subject: Re: 9.6 query slower than 9.5.3
Date: Thu, 16 Jun 2016 22:09:53 -0400
Message-ID: <CAMjNa7eNg538eSD9tzt7AC_S2b+AAdoZe0J5yLTK7w_gTFta_w@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
References: <CAMjNa7eYj3O2K5WxVAmMmYVUh_XpvS4db0LSKxd-kk_ZgaMitg@mail.gmail.com>
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I analyzed all tables involved after loading, and also while trying to
diagnose this issue.

I have the same statistics target settings on both servers.

Here are the schemas for the tables:

On Thu, Jun 16, 2016 at 10:04 PM, Tom Lane <[email protected]> wrote:

> Adam Brusselback <[email protected]> writes:
> > Hey all, testing out 9.6 beta 1 right now on Debian 8.5.
> > I have a query that is much slower on 9.6 than 9.5.3.
>
> The rowcount estimates in 9.6 seem way off.  Did you ANALYZE the tables
> after loading them into 9.6?  Maybe you forgot some statistics target
> settings?
>
> If it's not that, I wonder whether the misestimates are connected to the
> foreign-key-based estimation feature.  Are there any FKs on the tables
> involved?  May we see the table schemas?
>
>                         regards, tom lane
>

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