Re: Priorities for users or queries?

From: Benjamin Arai <benjamin(at)araisoft(dot)com>
To: Magnus Hagander <magnus(at)hagander(dot)net>
Cc: Adam Rich <adam(dot)r(at)sbcglobal(dot)net>, pgsql-general(at)postgresql(dot)org
Subject: Re: Priorities for users or queries?
Date: 2007-02-11 18:02:01
Message-ID: 45CF5A19.1010101@araisoft.com
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Hi Magnus,

Think this can be avoided as long the the queries executed on the lower
priority process never lock anything important. In my case, I would
alway be doing inserts with the lower priority process, so inversion
should never occur. On the other hand if some lock occur somewhere else
specific to Postgres then there may be an issue. Are there any other
tables locked by the the Postgres process other than those locks
explicitly set by the query?

Benjamin

Magnus Hagander wrote:
> Most likely, you do not want to do this. You *can* do it, but you are
> quite likely to suffer from priority inversion
> (http://en.wikipedia.org/wiki/Priority_inversion)
>
> //Magnus
>
>
> Adam Rich wrote:
>
>> There is a function pg_backend_pid() that will return the PID for
>> the current session. You could call this from your updating app
>> to get a pid to feed to the NICE command.
>>
>>
>> -----Original Message-----
>> From: pgsql-general-owner(at)postgresql(dot)org
>> [mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Benjamin Arai
>> Sent: Saturday, February 10, 2007 6:56 PM
>> To: pgsql-general(at)postgresql(dot)org; pgsql-admin(at)postgresql(dot)org
>> Subject: [GENERAL] Priorities for users or queries?
>>
>>
>> Hi,
>>
>> Is there a way to give priorities to queries or users? Something
>> similar to NICE in Linux. My goal is to give the updating (backend)
>> application a very low priority and give the web application a high
>> priority to avoid disturbing the user experience.
>>
>> Thanks in advance!
>>
>> Benjamin
>>
>>
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>>
>
>

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