Re: Queries intermittently slow

Поиск
Список
Период
Сортировка
От Scott Rankin
Тема Re: Queries intermittently slow
Дата
Msg-id DC594B9F-BB6B-4AA8-A3F4-B3A47EE29112@motus.com
обсуждение исходный текст
Ответ на Re: Queries intermittently slow  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: Queries intermittently slow  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-performance
On 1/6/16, 10:38 AM, "Tom Lane" <tgl@sss.pgh.pa.us> wrote:

>
>A possible theory is that the slow cases represent times when the desired
>page is not in cache, but you'd have to have a seriously overloaded disk
>subsystem for a disk fetch to take hundreds of ms.  Unless maybe this is
>running on some cloud service with totally unspecified I/O bandwidth?

This intrigues me. We are running on a, shall we say, less than name-brand cloud provider at the moment (transitioning
toAWS later this month).  Is there a reasonably straightforward way of confirming this hypothesis? We have had many
performanceissues with this vendor in the past, so I wouldn’t be surprised.
 

>
>> I will look at changing the deadlock_timeout, but that might have to wait for the weekend since this is a production
system.
>
>You needn't restart the server for that, just edit postgresql.conf and
>SIGHUP the postmaster.

Yep, we just try to limit any database changes until off-hours unless it’s an emergency.

>
>regards, tom lane

Thanks,
Scott
This email message contains information that Motus, LLC considers confidential and/or proprietary, or may later
designateas confidential and proprietary. It is intended only for use of the individual or entity named above and
shouldnot be forwarded to any other persons or entities without the express consent of Motus, LLC, nor should it be
usedfor any purpose other than in the course of any potential or actual business relationship with Motus, LLC. If the
readerof this message is not the intended recipient, or the employee or agent responsible to deliver it to the intended
recipient,you are hereby notified that any dissemination, distribution, or copying of this communication is strictly
prohibited.If you have received this communication in error, please notify sender immediately and destroy the original
message.

Internal Revenue Service regulations require that certain types of written advice include a disclaimer. To the extent
thepreceding message contains advice relating to a Federal tax issue, unless expressly stated otherwise the advice is
notintended or written to be used, and it cannot be used by the recipient or any other taxpayer, for the purpose of
avoidingFederal tax penalties, and was not written to support the promotion or marketing of any transaction or matter
discussedherein.
 

В списке pgsql-performance по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: Queries intermittently slow
Следующее
От: Tom Lane
Дата:
Сообщение: Re: Queries intermittently slow