Horton

Re: BUG #18429: Inconsistent results on similar queries with join lateral

David G. Johnston <david.g.johnston@gmail.com>

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From: "David G. Johnston" <david.g.johnston@gmail.com>
To: "b.ryder@ateme.com" <b.ryder@ateme.com>, "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>
Date: 2024-04-12T13:52:54Z
Lists: pgsql-bugs 
On Friday, April 12, 2024, PG Bug reporting form <noreply@postgresql.org>
wrote:

> The following bug has been logged on the website:
>
> Bug reference:      18429
> Logged by:          Benoît Ryder
> Email address:      b.ryder@ateme.com
> PostgreSQL version: 15.6
> Operating system:   Debian
> Description:
>
> -- `where` clause should return false: (14 - 6) / 4 = (12 - 6) / 4 → false
> select 1 from c2 where (14 - c2.t) / c2.d = (12 - c2.t) / c2.
>

You are doing integer division here and the right hand side equals, 1.5; I
suppose something may have used to round that up to the integer 2 which
would make both sides equals but now (v16) rounds it down (or more
accurately truncates it) to 1.

David J.

Commits

  1. Ensure generated join clauses for child rels have correct relids.

  2. Fix generation of EC join conditions at the wrong plan level.

  3. Make Vars be outer-join-aware.