Horton

Re: Improving isolationtester's data output

Noah Misch <noah@leadboat.com>

View thread View on postgr.es
From: Noah Misch <noah@leadboat.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, Alvaro Herrera <alvherre@alvh.no-ip.org>, pgsql-hackers@lists.postgresql.org
Date: 2021-06-16T03:43:23Z
Lists: pgsql-hackers 
On Tue, Jun 15, 2021 at 09:43:31PM -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > On 2021-06-15 19:26:25 -0400, Tom Lane wrote:
> >> Going forward it wouldn't be a problem, but back-patching isolation
> >> test cases might find it annoying.  On the other hand, my nearby
> >> patch to improve isolation test stability is already going to create
> >> issues of that sort.  (Unless, dare I say it, we back-patch that.)
> 
> > It might be worth to back-patch - aren't there some back branch cases of
> > test instability? And perhaps more importantly, I'm sure we'll encounter
> > cases of writing new isolation tests in the course of fixing bugs that
> > we'd want to backpatch that are hard to make reliable without the new
> > features?
> 
> Yeah, there absolutely is a case to back-patch things like this.  Whether
> it's a strong enough case, I dunno.  I'm probably too close to the patch
> to have an unbiased opinion about that.
> 
> However, a quick look through the commit history finds several places
> where we complained about not being able to back-patch isolation tests to
> before 9.6 because we hadn't back-patched that version's isolationtester
> improvements.  I found 6b802cfc7, 790026972, c88411995, 8b21b416e without
> looking too hard.  So that history certainly suggests that not
> back-patching such test infrastructure is the Wrong Thing.

I'm +1 for back-patching this class of change.  I've wasted time adapting a
back-patch's test case to account for non-back-patched test infrastructure
changes.  Every back-patch of test infrastructure has been a strict win from
my perspective.

Commits

  1. Improve display of query results in isolation tests.

  2. Detect unused steps in isolation specs and do some cleanup

  3. Remove dry-run mode from isolationtester