public inbox for [email protected]  

help / color / mirror / Atom feed

From: Tom Lane <[email protected]>
To: Nicolas Adenis-Lamarre <[email protected]>
Cc: Tender Wang <[email protected]>
Cc: [email protected]
Subject: Re: Planner : anti-join on left joins
Date: Thu, 01 Jan 2026 13:06:31 -0500
Message-ID: <[email protected]> (raw)
In-Reply-To: <CACPGbcvDA1K9tUM6hnS_X0-vDjoCZANm9XZsFcXy_UrXuL-hEA@mail.gmail.com>
References: <CACPGbctKMDP50PpRH09in+oWbHtZdahWSroRstLPOoSDKwoFsw@mail.gmail.com>
	<[email protected]>
	<CAHewXN=K_CTSzcm8t5ZQZ0TYn1nr+FVosTnoT4TY5EwRoXJL3w@mail.gmail.com>
	<CACPGbcvDA1K9tUM6hnS_X0-vDjoCZANm9XZsFcXy_UrXuL-hEA@mail.gmail.com>

Nicolas Adenis-Lamarre <[email protected]> writes:
> i added locally some regressions tests for such detection, but i needed to
> add cols to tenk1 cause tenk1 has no "not null" columns nor primary keys.
> i'm too new to tell if that's the correct way to do.

It is absolutely not.  In general, modifying the properties of any
of the commonly-used objects made by test_setup.sql is a bad idea.
There's too much risk of side-effects on other tests.  Even if they
don't show visible output changes, the code might now be following
some other code path and thus not testing what was intended.  This
seems particularly risky for changes in constraints, which might
change planner decisions.

If you need a table that's not like any existing test table, make a
new one.  But in this case it seems like there are probably existing
tests that cover behavior adjacent to what you want to test.  Maybe
you can re-use some of their tables and not have to expend test cycles
on building a whole new table.

			regards, tom lane

view thread (13+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: Planner : anti-join on left joins
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox