Re: RES: Priority to a mission critical transaction

Before asking them to remove it, are we sure priority inversion
is really a problem?

I thought this paper: http://www.cs.cmu.edu/~bianca/icde04.pdf
did a pretty good job at studying priority inversion on RDBMs's
including PostgreSQL on various workloads (TCP-W and TCP-C) and
found that the benefits of setting priorities vastly outweighed
the penalties of priority inversion across all the databases and
all the workloads they tested.



Bruce Momjian wrote:
> Someone should ask them to remove the article.
>
> ---------------------------------------------------------------------------
>
> Tom Lane wrote:
>> "Carlos H. Reimer" <carlos.reimer@opendb.com.br> writes:
>>> There is an article about "Lowering the priority of a PostgreSQL query"
>>> (http://weblog.bignerdranch.com/?p=11) that explains how to use the
>>> setpriority() to lower PostgreSQL processes.
>>> I?m wondering how much effective it would be for i/o bound systems.
>> That article isn't worth the electrons it's written on.  Aside from the
>> I/O point, there's a little problem called "priority inversion".  See
>> the archives for (many) past discussions of nice'ing backends.
>>
>>             regards, tom lane
>>
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>