From: Craig James <craig_james@emolecules.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: David Rees <drees76@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Occasional giant spikes in CPU load
Date: Wed, 07 Apr 2010 19:06:15 -0700
Message-ID: <4BBD3A17.90209@emolecules.com> (raw)
In-Reply-To: <r2q603c8f071004071747n3e56d12bo11c49885b8c2eb2e@mail.gmail.com>
References: <k2pda0294261004061437p9cd3810dqe9ce528b6ddb0873@mail.gmail.com>
<m2m603c8f071004071413w1f2d2497hbbe07d9c6491848f@mail.gmail.com>
<4BBCFB12.1010306@emolecules.com>
<y2r72dbd3151004071556j22244233l8fa1db295b7f9cd3@mail.gmail.com>
<r2q603c8f071004071747n3e56d12bo11c49885b8c2eb2e@mail.gmail.com>
On 4/7/10 5:47 PM, Robert Haas wrote:
> On Wed, Apr 7, 2010 at 6:56 PM, David Rees<drees76@gmail.com> wrote:
>>> max_fsm_pages = 16000000
>>> max_fsm_relations = 625000
>>> synchronous_commit = off
>>
>> You are playing with fire here. You should never turn this off unless
>> you do not care if your data becomes irrecoverably corrupted.
>
> That is not correct. Turning off synchronous_commit is sensible if
> you don't mind losing the last few transactions on a crash. What will
> corrupt your database is if you turn off fsync.
A bit off the original topic, but ...
I set it this way because I was advised that with a battery-backed RAID controller, this was a safe setting. Is that not the case?
Craig
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To: pgsql-performance@postgresql.org
Cc: craig_james@emolecules.com, robertmhaas@gmail.com, drees76@gmail.com
Subject: Re: Occasional giant spikes in CPU load
In-Reply-To: <4BBD3A17.90209@emolecules.com>
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