From 5ac10155eb62eb79db5f26a36d229f8af6f27bcc Mon Sep 17 00:00:00 2001
From: seonghobae <8172694+seonghobae@users.noreply.github.com>
Date: Sat, 1 Aug 2026 02:01:56 +0000
Subject: [PATCH 1/2] =?UTF-8?q?=E2=9A=A1=20Bolt:=20Optimize=20handle=20ID?=
 =?UTF-8?q?=20generation=20to=20reduce=20GC=20overhead?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .jules/bolt.md                  |  3 +++
 frontend/src/erd/handleUtils.ts | 18 +++++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/.jules/bolt.md b/.jules/bolt.md
index f1a8c146..c8249f3e 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -77,3 +77,6 @@ Optimized metric route processing to O(N) by creating a mapping of routes direct
 ## 2024-07-13 - [Optimize Export Dictionary FK lookups]
 **Learning:** Found O(N * C * E) performance bottleneck in ERD export dictionaries due to repeated array searching with `edges.some()` inside a nested loop over nodes and columns.
 **Action:** Replace repeated linear array scans for edges by precomputing O(1) Set lookups of foreign key column handles per node before looping.
+## 2024-07-28 - Avoid Array.from for String Iteration in High-Frequency Paths
+**Learning:** Using `Array.from(string, callback).join("-")` for string processing creates unnecessary intermediate array allocations, adding garbage collection (GC) pressure, especially when executed in high-frequency paths like generating handle IDs for nodes and edges in large graphs.
+**Action:** Replace `Array.from(string)` processing with a standard `for...of` loop (which natively supports Unicode code point iteration) and direct string concatenation to eliminate array allocations and improve execution speed.
diff --git a/frontend/src/erd/handleUtils.ts b/frontend/src/erd/handleUtils.ts
index 054d5ab2..4c1e75d4 100644
--- a/frontend/src/erd/handleUtils.ts
+++ b/frontend/src/erd/handleUtils.ts
@@ -1,10 +1,18 @@
 export function sanitizeHandleId(columnName: string): string {
-  const encoded = Array.from(columnName, (char) => {
-    // Array.from only yields non-empty Unicode scalars, so codePointAt(0) is defined.
-    return char.codePointAt(0)!.toString(16).padStart(4, '0')
-  }).join('-')
+  if (!columnName) return 'c-empty';
 
-  return `c-${encoded || 'empty'}`
+  let encoded = '';
+  let isFirst = true;
+  for (const char of columnName) {
+    if (!isFirst) {
+      encoded += '-';
+    }
+    // for...of correctly iterates over Unicode code points in JavaScript strings
+    encoded += char.codePointAt(0)!.toString(16).padStart(4, '0');
+    isFirst = false;
+  }
+
+  return `c-${encoded}`;
 }
 
 export function sourceColumnHandleId(columnName: string): string {

From 30d5ad73c672b3ab8bed504b5453cfa80283bb84 Mon Sep 17 00:00:00 2001
From: seonghobae <8172694+seonghobae@users.noreply.github.com>
Date: Mon, 3 Aug 2026 00:49:01 +0000
Subject: [PATCH 2/2] =?UTF-8?q?=E2=9A=A1=20Bolt:=20Optimize=20handle=20ID?=
 =?UTF-8?q?=20generation=20to=20reduce=20GC=20overhead?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit