Re: Strange runtime partition pruning behaviour with 11.4

From: MichaelDBA <MichaelDBA(at)sqlexec(dot)com>
To: Thomas Kellerer <spam_eater(at)gmx(dot)net>
Cc: pgsql-performance(at)lists(dot)postgresql(dot)org
Subject: Re: Strange runtime partition pruning behaviour with 11.4
Date: 2019-08-03 16:49:14
Message-ID: eb26974b-c2b8-ce68-8aa0-5a300f308c02@sqlexec.com
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I too got the same plan (non runtime partition pruning plan) with or
without the statistics.  So it looks like the workaround until this is
fixed is to re-arrange the query to do a subselect to force the runtime
partition pruning as Andreas suggested, which I tested and indeed does
work for me too!

Regards,
Michael Vitale

Thomas Kellerer wrote on 8/3/2019 10:06 AM:
>> it's posible to rewrite the query to:
>>
>>
>> test=# explain analyse select count(*) from foo_bar_baz as fbb where
>> foo_id = (select foo_id from foo where foo_name = 'eeny');
>>
>> I know, that's not a solution, but a workaround. :-(
>
> Yes, I discovered that as well.
>
> But I'm more confused (or concerned) by the fact that the (original)
> query works correctly *without* statistics.
>
> Thomas
>
>
>
>
>

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