Re: Enabling Checksums

On 5 December 2012 23:40, Robert Haas <robertmhaas@gmail.com> wrote:
> On Tue, Dec 4, 2012 at 6:17 PM, Jeff Davis <pgsql@j-davis.com> wrote:
>> Or, I could write up a test framework in ruby or python, using the
>> appropriate pg driver, and some not-so-portable shell commands to start
>> and stop the server. Then, I can publish that on this list, and that
>> would at least make it easier to test semi-manually and give greater
>> confidence in pre-commit revisions.
>
> That latter approach is similar to what happened with SSI's isolation
> tester.  It started out in Python, and then Heikki rewrote it in C.
> If Python/Ruby code is massively simpler to write than the C code,
> that might be a good way to start out.  It'll be an aid to reviewers
> even if neither it nor any descendent gets committed.
>
> Frankly, I think some automated testing harness (written in C or Perl)
> that could do fault-injection tests as part of the buildfarm would be
> amazingly awesome.  I'm drooling just thinking about it.  But I guess
> that's getting ahead of myself.

Agreed, though we can restrict that to a few things at first.

* Zeroing pages, making pages all 1s
* Transposing pages
* Moving chunks of data sideways in a block
* Flipping bits randomly
* Flipping data endianness
* Destroying particular catalog tables or structures

etc

As a contrib module, so we can be sure to never install it. ;-)

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services