Horton

Re: BUG #19435: Error: "No relation entry for relid 2" Triggered by Complex Join with Self-Referencing Tables

Andrei Lepikhov <lepihov@gmail.com>

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From: Andrei Lepikhov <lepihov@gmail.com>
To: Alexander Korotkov <aekorotkov@gmail.com>, Tender Wang <tndrwang@gmail.com>
Cc: Kirill Reshke <reshkekirill@gmail.com>, Fujii Masao <masao.fujii@gmail.com>, ammmkilo@163.com, pgsql-bugs@lists.postgresql.org
Date: 2026-03-18T12:18:27Z
Lists: pgsql-bugs

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On 18/3/26 09:40, Alexander Korotkov wrote:
> What about being more generic and call ChangeVarNodes_walker() for the
> node in ChangeVarNodesWalkExpression()?  It also works with out case
> and avoids code duplication.
I’ve reached the same conclusion. We lost a possible case when the 
RestrictInfo→clause contains a bare Var that isn’t pushed into either 
the left or right subtree.
I think we can fix this by replacing the expression walker with 
ChangeVarNodes_walker().
What is the reason for the second change? Tender, can you show us how to 
reproduce the issue so we can support your update to 
restrict_infos_logically_equal? If we include it, we should add a test.

-- 
regards, Andrei Lepikhov,
pgEdge

Commits

  1. Further improve commentary about ChangeVarNodesWalkExpression()

  2. Improve commentary about ChangeVarNodesWalkExpression().

  3. Fix self-join removal to update bare Var references in join clauses

  4. Implement Self-Join Elimination