nocfbot-0077-Improve-comment-accuracy-in-RPR-parse-analysis-an.txt

From f81b960cdbb073b492dd6b3afb83d1b4f2578a10 Mon Sep 17 00:00:00 2001
From: Henson Choi <assam258@gmail.com>
Date: Thu, 11 Jun 2026 09:41:54 +0900
Subject: [PATCH 77/77] Improve comment accuracy in RPR parse analysis and
 tests

Describe what transformRPR() actually does: it sets the AFTER MATCH SKIP
TO and INITIAL flags rather than "storing" or "transforming" those
clauses, and simplify the file header by dropping a vague pointer to the
planner.  In the regression tests, note that SEEK mode is not supported
and drop a stale optimizer file-path reference from a comment.
---
 src/backend/parser/parse_rpr.c         | 15 ++++++---------
 src/test/regress/expected/rpr_base.out |  5 ++---
 src/test/regress/sql/rpr_base.sql      |  6 ++----
 3 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/src/backend/parser/parse_rpr.c b/src/backend/parser/parse_rpr.c
index a1cd5ad8d38..3eaea2be750 100644
--- a/src/backend/parser/parse_rpr.c
+++ b/src/backend/parser/parse_rpr.c
@@ -7,11 +7,8 @@
  * structures during query analysis:
  *   - Validates frame options (must start at CURRENT ROW, no EXCLUDE)
  *   - Validates PATTERN variable count (max RPR_VARID_MAX + 1)
- *   - Transforms DEFINE clause into TargetEntry list
- *   - Stores PATTERN/SKIP TO/INITIAL clauses for planner
- *
- * Pattern optimization and compilation to NFA bytecode happens later
- * in the planner (see optimizer/plan/rpr.c).
+ *   - Transforms DEFINE clause
+ *   - Stores the PATTERN AST and the SKIP TO/INITIAL flags
  *
  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
@@ -67,8 +64,8 @@ static bool define_walker(Node *node, void *context);
  *
  * Validates and transforms RPR clauses from parse tree to planner structures:
  *   - Validates frame options (must start at CURRENT ROW, no EXCLUDE)
- *   - Stores AFTER MATCH SKIP TO clause
- *   - Stores SEEK/INITIAL clause
+ *   - Set AFTER MATCH SKIP TO flag
+ *   - Set SEEK/INITIAL flag
  *   - Transforms DEFINE clause into TargetEntry list
  *   - Stores PATTERN AST for deparsing (optimization happens in planner)
  *
@@ -174,10 +171,10 @@ transformRPR(ParseState *pstate, WindowClause *wc, WindowDef *windef,
 								   windef->frameLocation >= 0 ?
 								   windef->frameLocation : windef->location));
 
-	/* Transform AFTER MATCH SKIP TO clause */
+	/* Assign AFTER MATCH SKIP TO flag */
 	wc->rpSkipTo = windef->rpCommonSyntax->rpSkipTo;
 
-	/* Transform SEEK or INITIAL clause */
+	/* Assign INITIAL flag */
 	wc->initial = windef->rpCommonSyntax->initial;
 
 	/* Transform DEFINE clause into list of TargetEntry's */
diff --git a/src/test/regress/expected/rpr_base.out b/src/test/regress/expected/rpr_base.out
index f73758ee22d..41541898f5a 100644
--- a/src/test/regress/expected/rpr_base.out
+++ b/src/test/regress/expected/rpr_base.out
@@ -1927,7 +1927,6 @@ ORDER BY type, id;
 (16 rows)
 
 DROP TABLE rpr_skip;
--- INITIAL clause
 CREATE TABLE rpr_init (id INT, val INT);
 INSERT INTO rpr_init VALUES (1, 10), (2, 20), (3, 30), (4, 40);
 -- Explicit INITIAL
@@ -1971,7 +1970,7 @@ DROP TABLE rpr_init;
 -- SEEK
 CREATE TABLE rpr_seek (id INT, val INT);
 INSERT INTO rpr_seek VALUES (1, 10);
--- SEEK keyword
+-- SEEK keyword, SEEK mode is not supported
 SELECT COUNT(*) OVER w
 FROM rpr_seek
 WINDOW w AS (
@@ -3684,7 +3683,7 @@ WINDOW w1 AS (
 -- ============================================================
 -- Pattern Optimization Tests
 -- ============================================================
--- Tests for pattern optimization in optimizer/plan/rpr.c
+-- Tests for pattern optimization
 -- Use EXPLAIN to verify optimized pattern (shown as "Pattern: ...")
 CREATE TABLE rpr_plan (id INT, val INT);
 INSERT INTO rpr_plan VALUES
diff --git a/src/test/regress/sql/rpr_base.sql b/src/test/regress/sql/rpr_base.sql
index 7bb45b6bcf4..fcefd59de4a 100644
--- a/src/test/regress/sql/rpr_base.sql
+++ b/src/test/regress/sql/rpr_base.sql
@@ -1389,8 +1389,6 @@ ORDER BY type, id;
 
 DROP TABLE rpr_skip;
 
--- INITIAL clause
-
 CREATE TABLE rpr_init (id INT, val INT);
 INSERT INTO rpr_init VALUES (1, 10), (2, 20), (3, 30), (4, 40);
 
@@ -1424,7 +1422,7 @@ DROP TABLE rpr_init;
 CREATE TABLE rpr_seek (id INT, val INT);
 INSERT INTO rpr_seek VALUES (1, 10);
 
--- SEEK keyword
+-- SEEK keyword, SEEK mode is not supported
 SELECT COUNT(*) OVER w
 FROM rpr_seek
 WINDOW w AS (
@@ -2444,7 +2442,7 @@ WINDOW w1 AS (
 -- ============================================================
 -- Pattern Optimization Tests
 -- ============================================================
--- Tests for pattern optimization in optimizer/plan/rpr.c
+-- Tests for pattern optimization
 -- Use EXPLAIN to verify optimized pattern (shown as "Pattern: ...")
 
 CREATE TABLE rpr_plan (id INT, val INT);
-- 
2.50.1 (Apple Git-155)