Re: slow get_actual_variable_range with long running transactions - Mailing list pgsql-hackers

From Marc Cousin
Subject Re: slow get_actual_variable_range with long running transactions
Date
Msg-id e6c34df6-9c15-ad3b-1834-4464080c11b9@gmail.com
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In response to Re: slow get_actual_variable_range with long running transactions  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: slow get_actual_variable_range with long running transactions
List pgsql-hackers
Oh, sorry about that, I forgot to detail this. I tested on both 10.13 (which is the production environment on which we
facedthis), and on 12.3, with the same problem. 

On 16/06/2020 17:51, Tom Lane wrote:
> Marc Cousin <cousinmarc@gmail.com> writes:
>> Of course, what happens here is that the histogram says that max(a) is 1000000, and get_actual_variable_range
verifiesthe real upper bound. And has to read quite a few dead index records. 
>
> We've revised that logic several times to reduce the scope of the
> problem.  Since you didn't say which PG version you're using exactly,
> it's hard to offer any concrete suggestions.  But I fear there's
> not a lot you can do about it, other than upgrading if you're on a
> pre-v11 release.
>
>             regards, tom lane
>


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