Horton

Re: [PATCH] random_normal function

Tom Lane <tgl@sss.pgh.pa.us>

View thread
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, Fabien COELHO <coelho@cri.ensmp.fr>, Michael Paquier <michael@paquier.xyz>, Justin Pryzby <pryzby@telsasoft.com>, pgsql-hackers@postgresql.org, Paul Ramsey <pramsey@cleverelephant.ca>
Date: 2023-01-19T06:01:35Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Round off random_normal() test results one more decimal place.

  2. Remove pg_regress' never-documented "ignore" feature.

  3. Upgrade the random.sql regression test.

  4. Invent random_normal() to provide normally-distributed random numbers.

Andrey Lepikhov <a.lepikhov@postgrespro.ru> writes:
> On 1/9/23 23:52, Tom Lane wrote:
>> BTW, if this does bring the probability of failure down to the
>> one-in-a-billion range, I think we could also nuke the whole
>> "ignore:" business, simplifying pg_regress and allowing the
>> random test to be run in parallel with others.

> We have used the pg_sleep() function to interrupt a query at certain 
> execution phase. But on some platforms, especially in containers, the 
> query can vary execution time in so widely that the pg_sleep() timeout, 
> required to get rid of dependency on a query execution time, has become 
> unacceptable. So, the "ignore" option was the best choice.

But does such a test have any actual value?  If your test infrastructure
ignores the result, what makes you think you'd notice if the test did
indeed detect a problem?

I think "ignore:" was a kluge we put in twenty-plus years ago when our
testing standards were a lot lower, and it's way past time we got
rid of it.

			regards, tom lane