Re: Fixing WAL instability in various TAP tests

On Sat, Sep 25, 2021 at 08:20:06AM -0700, Mark Dilger wrote:
> > On Sep 25, 2021, at 7:17 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >> Leaving the tests brittle wastes developer time.
> > 
> > Trying to make them proof against all possible settings would waste
> > a lot more time, though.
> 
> You may be right, but the conversation about "all possible settings" was
> started by Noah.

You wrote, "I would expect tests which fail under legal alternate GUC settings
to be hardened to explicitly set the GUCs as they need, rather than implicitly
relying on the defaults."  I read that as raising the general principle, not
just a narrow argument about max_wal_size.  We can discontinue talking about
the general principle and focus on max_wal_size.

> I was really just talking about tests that depend on wal
> files not being removed, but taking no action to guarantee that, merely
> trusting that under default settings they won't be.

As I said, +1 for making tests pass under the min_val of max_wal_size.  If you
want to introduce a max_wal_size=2 buildfarm member so it stays that way, +1
for that as well.