Bruce Guenter wrote:
>
> CRCs are designed to catch N-bit errors (ie N bits in a row with their
> values flipped). N is (IIRC) the number of bits in the CRC minus one.
> So, a 32-bit CRC can catch all 31-bit errors. That's the only guarantee
> a CRC gives. Everything else has a 1 in 2^32-1 cha
> CRCs are designed to catch N-bit errors (ie N bits in a row with their
> values flipped). N is (IIRC) the number of bits in the CRC minus one.
> So, a 32-bit CRC can catch all 31-bit errors. That's the only guarantee
> a CRC gives. Everything else has a 1 in 2^32-1 chance of producing the
>
On Wed, Dec 06, 2000 at 11:13:33PM +, Daniele Orlandi wrote:
> Bruce Guenter wrote:
> > - Assume that a CRC is a guarantee. A CRC would be a good addition to
> > help ensure the data wasn't broken by flakey drive firmware, but
> > doesn't guarantee consistency.
> Even a CRC per transactio
Bruce Guenter wrote:
>
> - Assume that a CRC is a guarantee. A CRC would be a good addition to
> help ensure the data wasn't broken by flakey drive firmware, but
> doesn't guarantee consistency.
Even a CRC per transaction (it could be a nice END record) ?
Bye!
--
Daniele
--
On Wed, Dec 06, 2000 at 11:15:26AM -0500, Tom Lane wrote:
> Zeugswetter Andreas SB <[EMAIL PROTECTED]> writes:
> > Yes, but there would need to be a way to verify the last page or
> > record from txlog when running on crap hardware.
> How exactly *do* we determine where the end of the valid log da
Tom Lane wrote:
>
> Zeugswetter Andreas SB <[EMAIL PROTECTED]> writes:
> > Yes, but there would need to be a way to verify the last page or
> > record from txlog when running on crap hardware.
>
> How exactly *do* we determine where the end of the valid log data is,
> anyway?
Couldn't you use a
Zeugswetter Andreas SB <[EMAIL PROTECTED]> writes:
> Yes, but there would need to be a way to verify the last page or
> record from txlog when running on crap hardware.
How exactly *do* we determine where the end of the valid log data is,
anyway?
regards, tom lane
> > > Sounds great! We can follow this way: when first after last
> > > checkpoint update to a page being logged, XLOG code can log
> > > not AM specific update record but entire page (creating backup
> > > "physical log"). During after crash recovery such pages will
> > > be redone first, ensur
> Right. This is very much the guarantee that RAID (non-zero) makes,
> except "other than disk hardware failure" is replaced by "other than
> the failure of two drives". RAID gives you that (very, very
> substantial
> boost which is why it is so popular for DB servers). It doesn't give
> you
> > > No, WAL does help, cause you can then pull in your last dump and recover
> > > up to the moment that power cable was pulled out of the wall ...
> >
> > False, on so many counts I can't list them all.
>
> would love to hear them ... I'm always opening to having my
> misunderstandings corre
> NO, I just tested how solid PgSQL is, I run a program busy inserting record into
>PG table, when I
> suddenly pulled out power from my machine and restarted PG, I can not insert any
>record into database
> table, all backends are dead without any respone (not core dump), note that I am
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