From: Tom Lane <tgl@sss.pgh.pa.us>
To: Michael Paquier <michael@paquier.xyz>
cc: Christoph Berg <myon@debian.org>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
        ma lz <ma100@hotmail.com>
Subject: Re: query_id: jumble names of temp tables for better pg_stat_statement UX
In-reply-to: <1831838.1742656359@sss.pgh.pa.us>
References: <ZbtabEYMaZ3-wcxv@paquier.xyz> <Z9iWXKGwkm8RAC93@msg.df7cb.de> <Z9ju-lB4r6fXcIKS@paquier.xyz> <Z9mkqplmUpQ4xG52@msg.df7cb.de> <Z9n_K2YGbadpzD_s@paquier.xyz> <Z9qybg3FxTUefRT7@msg.df7cb.de> <Z9y43-dRvb4EtxQ0@paquier.xyz> <Z92TLJ5MmSU_lyxa@msg.df7cb.de> <Z93sH12uzCQHfOo-@paquier.xyz> <Z96GJEmTnvHKz_Kn@msg.df7cb.de> <Z96Rz-4IEyRCS4ny@paquier.xyz> <1831838.1742656359@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Sat, 22 Mar 2025 11:12:39 -0400"
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Date: Sat, 22 Mar 2025 12:24:43 -0400
Message-ID: <80506.1742660683@sss.pgh.pa.us>
Archived-At: <https://www.postgresql.org/message-id/80506.1742660683%40sss.pgh.pa.us>
Precedence: bulk

I wrote:
> So my feeling is: if we think this is the behavior we want, let's do
> it across the board.  I suggest that we simply drop the relid from the
> jumble and use the table alias (that is, eref->aliasname) instead.

I experimented with this trivial fix (shown in-line to keep the cfbot
from thinking this is the patch-of-record):

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes=
.h
index 23c9e3c5abf..a54bbdc18b7 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1051,7 +1051,7 @@ typedef struct RangeTblEntry
 	/* user-written alias clause, if any */
 	Alias	   *alias pg_node_attr(query_jumble_ignore);
 	/* expanded reference names */
-	Alias	   *eref pg_node_attr(query_jumble_ignore);
+	Alias	   *eref;
 =

 	RTEKind		rtekind;		/* see above */
 =

@@ -1094,7 +1094,7 @@ typedef struct RangeTblEntry
 	 * tables to be invalidated if the underlying table is altered.
 	 */
 	/* OID of the relation */
-	Oid			relid;
+	Oid			relid pg_node_attr(query_jumble_ignore);
 	/* inheritance requested? */
 	bool		inh;
 	/* relation kind (see pg_class.relkind) */

This caused just one diff in existing regression test cases:

diff --git a/contrib/pg_stat_statements/expected/planning.out b/contrib/pg=
_stat_statements/expected/planning.out
index 3ee1928cbe9..c25b8b946fd 100644
--- a/contrib/pg_stat_statements/expected/planning.out
+++ b/contrib/pg_stat_statements/expected/planning.out
@@ -75,8 +75,9 @@ SELECT plans >=3D 2 AND plans <=3D calls AS plans_ok, ca=
lls, rows, query FROM pg_sta
   WHERE query LIKE 'SELECT COUNT%' ORDER BY query COLLATE "C";
  plans_ok | calls | rows |                query                 =

 ----------+-------+------+--------------------------------------
- t        |     4 |    4 | SELECT COUNT(*) FROM stats_plan_test
-(1 row)
+ f        |     1 |    1 | SELECT COUNT(*) FROM stats_plan_test
+ f        |     3 |    3 | SELECT COUNT(*) FROM stats_plan_test
+(2 rows)
 =

 -- Cleanup
 DROP TABLE stats_plan_test;

What's happening there is that there's an ALTER TABLE ADD COLUMN in
the test, so the executions after the first one see more entries
in eref->colnames and come up with a different jumble.  I think
we probably don't want that behavior; we only want to jumble the
table name.  So we'd still need the v3-0001 patch in some form to
allow annotating RangeTblEntry.eref with a custom jumble method
that'd only jumble the aliasname.

			regards, tom lane