0009-fix-window-dedup.txt

From d4c87cb2d5b7f35223dc3bfa9d71809c9fcb135e Mon Sep 17 00:00:00 2001
From: Henson Choi <assam258@gmail.com>
Date: Sun, 8 Mar 2026 18:30:21 +0900
Subject: [PATCH 09/12] Fix window deduplication for RPR windows at parse time

---
 src/backend/parser/parse_agg.c         |  3 ++-
 src/test/regress/expected/rpr_base.out | 26 ++++++++++++++++++++++++++
 src/test/regress/sql/rpr_base.sql      | 20 ++++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 81e1d70ffc1..5e942075444 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -1110,7 +1110,8 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
 				equal(refwin->orderClause, windef->orderClause) &&
 				refwin->frameOptions == windef->frameOptions &&
 				equal(refwin->startOffset, windef->startOffset) &&
-				equal(refwin->endOffset, windef->endOffset))
+				equal(refwin->endOffset, windef->endOffset) &&
+				equal(refwin->rpCommonSyntax, windef->rpCommonSyntax))
 			{
 				/* found a duplicate window specification */
 				wfunc->winref = winref;
diff --git a/src/test/regress/expected/rpr_base.out b/src/test/regress/expected/rpr_base.out
index 2fefb933c71..09d079b05c6 100644
--- a/src/test/regress/expected/rpr_base.out
+++ b/src/test/regress/expected/rpr_base.out
@@ -14,6 +14,7 @@
 --   SKIP TO / INITIAL Tests
 --   Serialization/Deserialization Tests (objects kept for pg_upgrade/pg_dump)
 --   Error Cases Tests
+--   Window Deduplication Tests
 --
 -- Planner Layer:
 --   Pattern Optimization Tests
@@ -2968,6 +2969,31 @@ ORDER BY id;
 (3 rows)
 
 DROP TABLE rpr_null;
+-- ============================================================
+-- Window Deduplication Tests
+-- ============================================================
+-- non-RPR and RPR windows with identical base frame are kept separate.
+SELECT id, val,
+    first_value(id) OVER (
+        ORDER BY id
+        ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+    ) AS fv_normal,
+    first_value(id) OVER w1 AS fv_rpr
+FROM (VALUES (1, 10), (2, 20), (3, 30), (4, 40)) AS t(id, val)
+WINDOW w1 AS (
+    ORDER BY id
+    ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+    PATTERN (A+)
+    DEFINE A AS val > 10
+);
+ id | val | fv_normal | fv_rpr 
+----+-----+-----------+--------
+  1 |  10 |         1 |       
+  2 |  20 |         2 |      2
+  3 |  30 |         3 |       
+  4 |  40 |         4 |       
+(4 rows)
+
 -- ============================================================
 -- Pattern Optimization Tests
 -- ============================================================
diff --git a/src/test/regress/sql/rpr_base.sql b/src/test/regress/sql/rpr_base.sql
index 453860c1499..95cfb4b86fe 100644
--- a/src/test/regress/sql/rpr_base.sql
+++ b/src/test/regress/sql/rpr_base.sql
@@ -14,6 +14,7 @@
 --   SKIP TO / INITIAL Tests
 --   Serialization/Deserialization Tests (objects kept for pg_upgrade/pg_dump)
 --   Error Cases Tests
+--   Window Deduplication Tests
 --
 -- Planner Layer:
 --   Pattern Optimization Tests
@@ -2080,6 +2081,25 @@ ORDER BY id;
 
 DROP TABLE rpr_null;
 
+-- ============================================================
+-- Window Deduplication Tests
+-- ============================================================
+
+-- non-RPR and RPR windows with identical base frame are kept separate.
+SELECT id, val,
+    first_value(id) OVER (
+        ORDER BY id
+        ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+    ) AS fv_normal,
+    first_value(id) OVER w1 AS fv_rpr
+FROM (VALUES (1, 10), (2, 20), (3, 30), (4, 40)) AS t(id, val)
+WINDOW w1 AS (
+    ORDER BY id
+    ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+    PATTERN (A+)
+    DEFINE A AS val > 10
+);
+
 -- ============================================================
 -- Pattern Optimization Tests
 -- ============================================================
-- 
2.50.1 (Apple Git-155)