Re: visibility maps

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От Pavan Deolasee
Тема Re: visibility maps
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Msg-id 2e78013d0812110541tb80aea1sd8a03dee9b890534@mail.gmail.com
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Ответ на Re: visibility maps  (Zdenek Kotala <Zdenek.Kotala@Sun.COM>)
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On Thu, Dec 11, 2008 at 7:03 PM, Zdenek Kotala <Zdenek.Kotala@sun.com> wrote:

>
> Yes, because it is not simple write operation. You need to read byte from
> memory to register, set bit and write it back. Write memory itself is atomic
> but somebody could change other bits between read and write.
>

Yeah, but since its just a hint, we can possibly live with some corner
cases. The benefit of avoiding contention on the VM page would easily
out weigh the downside of wrong hints.

Thanks,
Pavan

-- 
Pavan Deolasee
EnterpriseDB     http://www.enterprisedb.com


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