Re: Enabling Checksums

On Tue, 2012-12-04 at 01:03 -0800, Jeff Davis wrote:
> > 3. I think we need an explicit test of this feature (as you describe
> > above), rather than manual testing. corruptiontester?
>
> I agree, but I'm not 100% sure how to proceed. I'll look at Kevin's
> tests for SSI and see if I can do something similar, but suggestions are
> welcome. A few days away, at the earliest.

I looked into this. The SSI tests still use pg_regress to start/stop the
server, and make use of a lot more of the pg_regress framework.
pg_regress doesn't fit what I need to do, at all.

For me, each test involves a fresh initdb, followed by a small data load
(at least a few pages). Then, I shut down the server, inject the faults
under test, and start the server back up. Then, I count the table and
expect an error. Then I throw away the data directory. (I can shortcut
some of the initdb and load time by keeping a good copy of the table
throughout the whole set of tests and copying it back, but that's just a
detail.)

So, I could try to write a test framework in C that would be a candidate
to include with the main distribution and be run by the buildfarm, but
that would be a lot of work. Even then, I couldn't easily abstract away
these kinds of tests into text files, unless I invent a language that is
suitable for describing disk faults to inject.

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.

Suggestions?

Regards,
Jeff Davis