Horton

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

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Andrei Lepikhov <lepihov@gmail.com>, Kirill Reshke <reshkekirill@gmail.com>, Tender Wang <tndrwang@gmail.com>, Fujii Masao <masao.fujii@gmail.com>, ammmkilo@163.com, pgsql-bugs@lists.postgresql.org
Date: 2026-03-23T21:34:31Z
Lists: pgsql-bugs 
Alexander Korotkov <aekorotkov@gmail.com> writes:
> Please, consider my additions to the comment.  They explain why we use
> ChangeVarNodes_walker() instead of expression_tree_walker(), and gives
> a bit more details about difference in processing of top-level Query
> and subquery.

I'm fine with this, although in

+ * ... We invoke ChangeVarNodes_walker directly rather than
+ * expression_tree_walker

I would write "rather than via expression_tree_walker".

			regards, tom lane

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