Re: Write ahead logging

Mario Weilguni wrote:
>>>So the question is: has anybody verified, that the log is written to disk
>>>before returning from commit?
>>
>>Some (or all?) IDE disks are known to lie:  they report success as
>>soon as the data have reached the drive's RAM.
>
>
> under linux, hdparm -W can turn off the write cache of IDE disk, maybe you
> should try with write-caching turned off.

Yes, that made a big difference. Latency went up to 25-95ms.

Regards,

    Matthias Meixner

--
Matthias Meixner                       meixner@informatik.tu-darmstadt.de
Technische Universität Darmstadt
Datenbanken und Verteilte Systeme              Telefon (+49) 6151 16 6232
Wilhelminenstraße 7, D-64283 Darmstadt, Germany    Fax (+49) 6151 16 6229