Re: Declarative partitioning - another take

From: Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Amit Langote <amitlangote09(at)gmail(dot)com>, Dmitry Ivanov <d(dot)ivanov(at)postgrespro(dot)ru>, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, Erik Rijkers <er(at)xs4all(dot)nl>, Rajkumar Raghuwanshi <rajkumar(dot)raghuwanshi(at)enterprisedb(dot)com>, Ashutosh Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org>, pgsql-hackers-owner(at)postgresql(dot)org
Subject: Re: Declarative partitioning - another take
Date: 2016-12-21 05:03:13
Message-ID: 2c1f36ea-41fe-09ab-e58e-8a78cee3a127@lab.ntt.co.jp
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On 2016/12/21 13:42, Robert Haas wrote:
> On Tue, Dec 20, 2016 at 9:14 PM, Amit Langote
> <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>> On 2016/12/21 1:45, Alvaro Herrera wrote:
>>> Robert Haas wrote:
>>>> On Tue, Dec 20, 2016 at 10:27 AM, Alvaro Herrera
>>>> <alvherre(at)2ndquadrant(dot)com> wrote:
>>>>> Even if we decide to keep the message, I think it's not very good
>>>>> wording anyhow; as a translator I disliked it on sight. Instead of
>>>>> "skipping scan to validate" I would use "skipping validation scan",
>>>>> except that it's not clear what it is we're validating. Mentioning
>>>>> partition constraint in errcontext() doesn't like a great solution, but
>>>>> I can't think of anything better.
>>>>
>>>> Maybe something like: partition constraint for table \"%s\" is implied
>>>> by existing constraints
>>>
>>> Actually, shouldn't we emit a message if we *don't* skip the check?
>>
>> Scanning (aka, not skipping) to validate the partition constraint is the
>> default behavior, so a user would be expecting it anyway, IOW, need not be
>> informed of it. But when ATExecAttachPartition's efforts to avoid the
>> scan by comparing the partition constraint against existing constraints
>> (which the user most probably deliberately added just for this) succeed,
>> that seems like a better piece of information to provide the user with,
>> IMHO. But then again, having a message printed before a potentially long
>> validation scan seems like something a user would like to see, to know
>> what it is that is going to take so long. Hmm.
>>
>> Anyway, what would the opposite of Robert's suggested message look like:
>> "scanning table \"%s\" to validate partition constraint"?
>
> Maybe: partition constraint for table \"%s\" is implied by existing constraints

OK, updated patch attached.

Thanks,
Amit

Attachment Content-Type Size
turn-elog-into-ereport-2.patch text/x-diff 1.7 KB

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