diff --git a/.jules/bolt.md b/.jules/bolt.md
index f1a8c1466..5a4b0e20b 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.
+## 2024-10-25 - ERD 내보내기 시 불필요한 O(N*C) 핸들 인코딩 제거
+**Learning:** Mermaid, Prisma 등 ERD 내보내기 과정에서 매 컬럼마다 호출되는 `sanitizeHandleId` 함수(O(N*C)) 내의 문자열 hex 인코딩이 심각한 성능 저하와 병목을 유발합니다. 또한 Prisma 내보내기에서는 핸들을 원래 컬럼명으로 취급하여 `@relation` 정의 시 잘못된 이름이 생성되는 버그가 있었습니다.
+**Action:** 엣지의 `edge.data.sourceColumns`를 우선 활용하여 O(1) 조회 Set을 미리 구성하고, 레거시 핸들이 없는 경우 `fkNodeHandlePairs.size > 0` 조건을 확인하여 O(N*C) 인코딩 연산을 완전히 우회합니다.
diff --git a/frontend/src/erd/exportDataDictionary.ts b/frontend/src/erd/exportDataDictionary.ts
index 0111660d9..6062000aa 100644
--- a/frontend/src/erd/exportDataDictionary.ts
+++ b/frontend/src/erd/exportDataDictionary.ts
@@ -78,8 +78,11 @@ function isForeignKeyColumn(
     return true;
   }
 
-  const handleId = sourceColumnHandleId(columnName);
-  return info.handles.has(handleId);
+  if (info.handles.size > 0) {
+    const handleId = sourceColumnHandleId(columnName);
+    return info.handles.has(handleId);
+  }
+  return false;
 }
 
 function exampleValue(value: TableNodeData['columns'][number]['example_value']): string {
diff --git a/frontend/src/erd/mermaid.ts b/frontend/src/erd/mermaid.ts
index 6e77a9bca..55e422eff 100644
--- a/frontend/src/erd/mermaid.ts
+++ b/frontend/src/erd/mermaid.ts
@@ -26,17 +26,27 @@ export function exportMermaid(
   }
 
   const fkNodeColumnPairs = new Set<string>();
+  const fkNodeHandlePairs = new Set<string>();
   const fkNodesWithoutHandles = new Set<string>();
 
   for (const edge of edges) {
-    if (edge.sourceHandle?.startsWith("src-")) {
-      fkNodeColumnPairs.add(`${edge.source}:${edge.sourceHandle.slice(4)}`);
+    const edgeData = edge.data as any;
+    if (edgeData?.sourceColumns) {
+      for (const col of edgeData.sourceColumns) {
+        fkNodeColumnPairs.add(`${edge.source}:${col}`);
+      }
+    } else if (edge.sourceHandle?.startsWith("src-")) {
+      fkNodeHandlePairs.add(`${edge.source}:${edge.sourceHandle.slice(4)}`);
     } else if (!edge.sourceHandle) {
       fkNodesWithoutHandles.add(edge.source);
     }
 
-    if (edge.targetHandle?.startsWith("tgt-")) {
-      fkNodeColumnPairs.add(`${edge.target}:${edge.targetHandle.slice(4)}`);
+    if (edgeData?.targetColumns) {
+      for (const col of edgeData.targetColumns) {
+        fkNodeColumnPairs.add(`${edge.target}:${col}`);
+      }
+    } else if (edge.targetHandle?.startsWith("tgt-")) {
+      fkNodeHandlePairs.add(`${edge.target}:${edge.targetHandle.slice(4)}`);
     }
   }
 
@@ -48,11 +58,15 @@ export function exportMermaid(
       let modifiers = "";
       if (col.is_pk) modifiers += " PK";
 
-      const safeId = sanitizeHandleId(col.column_name);
-      // ⚡ Bolt: O(1) lookups instead of O(E) array search for every column
-      const isFk =
-        fkNodeColumnPairs.has(`${node.id}:${safeId}`) ||
-        (fkNodesWithoutHandles.has(node.id) && node.data.badges?.fk);
+      // ⚡ Bolt: Use direct O(1) string matching against edge data to bypass expensive O(N*C) sanitizeHandleId encodings.
+      let isFk = fkNodeColumnPairs.has(`${node.id}:${col.column_name}`) ||
+                 (fkNodesWithoutHandles.has(node.id) && node.data.badges?.fk);
+
+      // Fallback only if there are legacy edges that require handle matching
+      if (!isFk && fkNodeHandlePairs.size > 0) {
+        const safeId = sanitizeHandleId(col.column_name);
+        isFk = fkNodeHandlePairs.has(`${node.id}:${safeId}`);
+      }
 
       if (isFk && !col.is_pk) modifiers += " FK";
 
diff --git a/frontend/src/erd/prisma.ts b/frontend/src/erd/prisma.ts
index 211dfdd8d..66ba51aec 100644
--- a/frontend/src/erd/prisma.ts
+++ b/frontend/src/erd/prisma.ts
@@ -57,6 +57,7 @@ export function exportPrisma(
   // Prisma relations require a field on both sides if we want back-relations,
   // but let's just generate the minimal required relations.
   const fkNodeColumnPairs = new Set<string>();
+  const fkNodeHandlePairs = new Set<string>();
   const fkNodesWithoutHandles = new Set<string>();
   const incomingRelationsByNode = new Map<string, Array<{ relationName: string, sourceModel: string, sourceField: string, isUnique: boolean }>>();
   const edgesProcessed = new Map<string, { sourceModel: string, targetModel: string, sourceFields: string[], targetFields: string[], relationName: string }>();
@@ -67,17 +68,23 @@ export function exportPrisma(
     if (!sourceNode || !targetNode) continue;
 
     const relName = sanitizeName(String(edge.label || `${sourceNode.data.title}_${targetNode.data.title}`));
+    const edgeData = edge.data as { sourceColumns?: string[], targetColumns?: string[] } | undefined;
 
     let sourceField = "";
-    if (edge.sourceHandle?.startsWith("src-")) {
-      sourceField = edge.sourceHandle.slice(4);
+    if (edgeData?.sourceColumns?.[0]) {
+      sourceField = edgeData.sourceColumns[0];
       fkNodeColumnPairs.add(`${edge.source}:${sourceField}`);
+    } else if (edge.sourceHandle?.startsWith("src-")) {
+      sourceField = edge.sourceHandle.slice(4); // Legacy encoded handle
+      fkNodeHandlePairs.add(`${edge.source}:${sourceField}`);
     } else if (!edge.sourceHandle) {
       fkNodesWithoutHandles.add(edge.source);
     }
 
     let targetField = "id"; // fallback
-    if (edge.targetHandle?.startsWith("tgt-")) {
+    if (edgeData?.targetColumns?.[0]) {
+      targetField = edgeData.targetColumns[0];
+    } else if (edge.targetHandle?.startsWith("tgt-")) {
       targetField = edge.targetHandle.slice(4);
     }
 
@@ -112,9 +119,12 @@ export function exportPrisma(
     for (const col of node.data.columns) {
       const fieldName = sanitizeName(col.column_name);
 
-      const isFk =
-        fkNodeColumnPairs.has(`${node.id}:${sanitizeHandleId(col.column_name)}`) ||
-        (fkNodesWithoutHandles.has(node.id) && node.data.badges?.fk);
+      let isFk = fkNodeColumnPairs.has(`${node.id}:${col.column_name}`) ||
+                 (fkNodesWithoutHandles.has(node.id) && node.data.badges?.fk);
+
+      if (!isFk && fkNodeHandlePairs.size > 0) {
+        isFk = fkNodeHandlePairs.has(`${node.id}:${sanitizeHandleId(col.column_name)}`);
+      }
 
       const prismaType = mapToPrismaType(col.data_type, isFk);