Hi, On 2024-06-25 13:26:23 +0300, Heikki Linnakangas wrote: > While fixing a recent bug on visibility on a standby [1], I wrote a > regression test that uses BackgroundPsql to run some queries in a > long-running psql session. The problem is that that was refactored in v17, > commit 664d757531. The test I wrote for v17 doesn't work as it is on > backbranches. Options: > > 1. Write the new test differently on backbranches. Before 664d757531, the > test needs to work a lot harder to use the background psql session, calling > pump() etc. That's doable, but as noted in the discussion that led to > 664d757531, it's laborious and error-prone. > > 2. Backport commit 664d757531. This might break out-of-tree perl tests that > use the background_psql() function. I don't know if any such tests exist, > and they would need to be changed for v17 anyway, so that seems acceptable. > Anyone aware of any extensions using the perl test modules? > > 3. Backport commit 664d757531, but keep the existing background_psql() > function unchanged. Add a different constructor to get the v17-style > BackgroundPsql session, something like "$node->background_psql_new()". > > I'm leaning towards 3. We might need to backport more perl tests that use > background_psql() in the future, backporting the test module will make that > easier. > > Thoughts?
Yes, I've wished for this a couple times. I think 2 or 3 would be reasonable. I think 1) often just leads to either tests not being written or being fragile... Greetings, Andres Freund
