Re: recovery_min_apply-delay and remote_apply

On Fri, Sep 16, 2016 at 5:55 PM, Thomas Munro
<thomas(dot)munro(at)enterprisedb(dot)com> wrote:
> On Sat, Sep 17, 2016 at 8:45 AM, Bernd Helmle <mailings(at)oopsware(dot)de> wrote:
>> Current PostgreSQL Documentation on recovery.conf has this about
>> recovery_min_apply_delay[1]:
>>
>> ---<---
>>
>> This parameter is intended for use with streaming replication deployments;
>> however, if the parameter is specified it will be honored in all cases.
>> Synchronous replication is not affected by this setting because there is
>> not yet any setting to request synchronous apply of transaction commits.
>>
>> --->---
>>
>> If i understand correctly, this is not true anymore with 9.6, where
>> remote_apply will have exactly the behavior the paragraph above wants to
>> contradict: any transaction executed with synchronous_commit=remote_apply
>> will wait at least recovery_min_apply_delay to finish. Given that
>> synchronous_commit can be controlled by any user, this might be dangerous
>> if someone doesn't take care enough.
>
> Yes, I missed that sentence. Thanks.
>
>> I think we need a doc patch for that at least, see attached patch against
>> master, but 9.6 should have a corrected one, too.
>
> +1

Committed with a bit of adjustment, and back-patched to 9.6.

--
Robert Haas
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