v9-0001-Sketch.patch

text/plain

Filename: v9-0001-Sketch.patch
Type: text/plain
Part: 0
Message: Re: MergeAppend could consider sorting cheapest child path

Patch

Same data as JSON: GET /api/v1/attachments/:id/patch the parsed metadata as JSON — format, series position, per-file stats; never the diff bytes. API reference →
Format: format-patch
Series: patch v9-0001
Subject: Sketch
File+
src/backend/optimizer/path/costsize.c 2 2
From cca6ed05cf8128a1e88ea07021ba21953cbc1a6b Mon Sep 17 00:00:00 2001
From: "Andrei V. Lepikhov" <lepihov@gmail.com>
Date: Thu, 31 Jul 2025 14:53:08 +0200
Subject: [PATCH v9 1/2] Sketch

---
 src/backend/optimizer/path/costsize.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 344a3188317..c353001c581 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -512,7 +512,7 @@ cost_gather_merge(GatherMergePath *path, PlannerInfo *root,
 	logN = LOG2(N);
 
 	/* Assumed cost per tuple comparison */
-	comparison_cost = 2.0 * cpu_operator_cost;
+	comparison_cost = 3.9 * cpu_operator_cost;
 
 	/* Heap creation cost */
 	startup_cost += comparison_cost * N * logN;
@@ -2474,7 +2474,7 @@ cost_merge_append(Path *path, PlannerInfo *root,
 	logN = LOG2(N);
 
 	/* Assumed cost per tuple comparison */
-	comparison_cost = 2.0 * cpu_operator_cost;
+	comparison_cost = 3.9 * cpu_operator_cost;
 
 	/* Heap creation cost */
 	startup_cost += comparison_cost * N * logN;
-- 
2.50.1