On Tue, Mar 25, 2025 at 07:24:20PM -0400, Tom Lane wrote: > fails to honor $query_jumble_ignore as the other if-branches do. > Perhaps it's unlikely that a node would have both query_jumble_custom > and query_jumble_ignore annotations, but still, the script would emit > completely incorrect code if it did. Also, the "# node type" comment > should probably be moved down to within the first "elsif" block.
Oops, sorry about that. Fixed both of these in 27ee6ede6bc9. > I'd change "semantically similar queries" to "otherwise-similar > queries"; I think writing "semantically" will just confuse people. If I get the difference right, semantically would apply to concepts related to linguistics, but that's not what we have here, so you are using a more general term. Thanks for the suggestions. -- Michael
From 30f8066989eac6f8c72034d3fb5150368c2821a9 Mon Sep 17 00:00:00 2001
From: Michael Paquier <mich...@paquier.xyz>
Date: Wed, 26 Mar 2025 09:17:41 +0900
Subject: [PATCH v7] Add custom query jumble function for RangeTblEntry.eref
---
src/include/nodes/parsenodes.h | 11 +++++++---
src/backend/nodes/queryjumblefuncs.c | 19 ++++++++++++++++++
doc/src/sgml/pgstatstatements.sgml | 9 +++++++--
.../pg_stat_statements/expected/select.out | 20 ++++++++-----------
4 files changed, 42 insertions(+), 17 deletions(-)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 23c9e3c5abf2..df331b1c0d99 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1050,8 +1050,13 @@ 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);
+
+ /*
+ * Expanded reference names. This uses a custom query jumble function so
+ * that the table name is included in the computation, but not its list of
+ * columns.
+ */
+ Alias *eref pg_node_attr(custom_query_jumble);
RTEKind rtekind; /* see above */
@@ -1094,7 +1099,7 @@ 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) */
diff --git a/src/backend/nodes/queryjumblefuncs.c b/src/backend/nodes/queryjumblefuncs.c
index f8b0f91704ba..62d6cfb7ac15 100644
--- a/src/backend/nodes/queryjumblefuncs.c
+++ b/src/backend/nodes/queryjumblefuncs.c
@@ -67,6 +67,9 @@ static void _jumbleElements(JumbleState *jstate, List *elements);
static void _jumbleA_Const(JumbleState *jstate, Node *node);
static void _jumbleList(JumbleState *jstate, Node *node);
static void _jumbleVariableSetStmt(JumbleState *jstate, Node *node);
+static void _jumbleRangeTblEntry_eref(JumbleState *jstate,
+ RangeTblEntry *rte,
+ Alias *expr);
/*
* Given a possibly multi-statement source string, confine our attention to the
@@ -516,3 +519,19 @@ _jumbleVariableSetStmt(JumbleState *jstate, Node *node)
JUMBLE_FIELD(is_local);
JUMBLE_LOCATION(location);
}
+
+/*
+ * Custom query jumble function for RangeTblEntry.eref.
+ */
+static void
+_jumbleRangeTblEntry_eref(JumbleState *jstate,
+ RangeTblEntry *rte,
+ Alias *expr)
+{
+ JUMBLE_FIELD(type);
+
+ /*
+ * This includes only the table name, the list of column names is ignored.
+ */
+ JUMBLE_STRING(aliasname);
+}
diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml
index f4e384e95aea..625b84ebfefd 100644
--- a/doc/src/sgml/pgstatstatements.sgml
+++ b/doc/src/sgml/pgstatstatements.sgml
@@ -675,8 +675,13 @@ calls | 2
things, the internal object identifiers appearing in this representation.
This has some counterintuitive implications. For example,
<filename>pg_stat_statements</filename> will consider two apparently-identical
- queries to be distinct, if they reference a table that was dropped
- and recreated between the executions of the two queries.
+ queries to be distinct, if they reference for example a function that was
+ dropped and recreated between the executions of the two queries.
+ Conversely, if a table is dropped and recreated between the
+ executions of queries, two apparently-identical queries may be
+ considered the same. However, if the alias for a table is different
+ for otherwise-similar queries, these queries will be considered
+ distinct.
The hashing process is also sensitive to differences in
machine architecture and other facets of the platform.
Furthermore, it is not safe to assume that <structfield>queryid</structfield>
diff --git a/contrib/pg_stat_statements/expected/select.out b/contrib/pg_stat_statements/expected/select.out
index 708c6b0e9c41..1eebc2898ab9 100644
--- a/contrib/pg_stat_statements/expected/select.out
+++ b/contrib/pg_stat_statements/expected/select.out
@@ -433,11 +433,10 @@ COMMIT;
SELECT calls, query FROM pg_stat_statements ORDER BY query COLLATE "C";
calls | query
-------+------------------------------------------------------------------------
- 1 | SELECT * FROM temp_t
- 1 | SELECT * FROM temp_t
+ 2 | SELECT * FROM temp_t
0 | SELECT calls, query FROM pg_stat_statements ORDER BY query COLLATE "C"
1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
-(4 rows)
+(3 rows)
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
@@ -623,18 +622,15 @@ SELECT a AS a1 FROM pgss_schema_2.tab_search_diff_2;
SELECT calls, query FROM pg_stat_statements ORDER BY query COLLATE "C";
calls | query
-------+------------------------------------------------------------------------
- 3 | SELECT a FROM pgss_schema_2.tab_search_diff_2 AS t1
- 9 | SELECT a FROM tab_search_diff_2 AS t1
- 1 | SELECT a, b FROM pgss_schema_1.tab_search_same
- 3 | SELECT a, b FROM tab_search_same
+ 8 | SELECT a FROM tab_search_diff_2
+ 4 | SELECT a FROM tab_search_diff_2 AS t1
+ 4 | SELECT a, b FROM tab_search_same
0 | SELECT calls, query FROM pg_stat_statements ORDER BY query COLLATE "C"
- 1 | SELECT count(*) FROM pgss_schema_1.tab_search_same
- 1 | SELECT count(*) FROM pgss_schema_2.tab_search_diff_1
- 3 | SELECT count(*) FROM tab_search_diff_1
+ 4 | SELECT count(*) FROM tab_search_diff_1
4 | SELECT count(*) FROM tab_search_diff_2
- 3 | SELECT count(*) FROM tab_search_same
+ 4 | SELECT count(*) FROM tab_search_same
1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
-(11 rows)
+(8 rows)
DROP SCHEMA pgss_schema_1 CASCADE;
NOTICE: drop cascades to 3 other objects
--
2.49.0
signature.asc
Description: PGP signature
