Re: Enabling Checksums

On 12/14/12 3:00 PM, Jeff Davis wrote:
> After some thought, I don't see much value in introducing multiple
> instances of corruption at a time. I would think that the smallest unit
> of corruption would be the hardest to detect, so by introducing many of
> them in one pass makes it easier to detect.

That seems reasonable. It would eliminate a lot of issues with
reproducing a fault too. I can just print the impacted block number
presuming it will show up in a log, and make it possible to override
picking one at random with a command line input.

> Does it make sense to have a separate executable (pg_corrupt) just for
> corrupting the data as a test? Or should it be part of a
> corruption-testing harness (pg_corruptiontester?), that introduces the
> corruption and then verifies that it's properly detected?

Let me see what falls out of the coding, I don't think this part needs
to get nailed down yet. Building a corruption testing harness is going
to involve a lot of creating new clusters and test data to torture.
It's a different style of problem than injecting faults in the first place.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
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