diff --git a/benchmark_harvest.py b/benchmark_harvest.py
new file mode 100644
index 0000000..e8a3cfb
--- /dev/null
+++ b/benchmark_harvest.py
@@ -0,0 +1,81 @@
+import sqlite3
+import time
+import pathlib
+import os
+
+# Set up test env
+vault_dir = pathlib.Path("./benchmark_vault")
+vault_dir.mkdir(exist_ok=True)
+db_path = vault_dir / "Meta" / ".cache" / "memory.db"
+(vault_dir / "Meta" / ".cache").mkdir(parents=True, exist_ok=True)
+
+conn = sqlite3.connect(db_path)
+conn.row_factory = sqlite3.Row
+
+# Create table
+conn.execute("""
+    CREATE TABLE IF NOT EXISTS candidates (
+        id TEXT PRIMARY KEY,
+        session_id TEXT,
+        status TEXT,
+        importance INTEGER,
+        target_dir TEXT,
+        title TEXT,
+        content TEXT,
+        source TEXT,
+        vault_path TEXT
+    )
+""")
+conn.commit()
+
+NUM_RECORDS = 500
+
+# Insert test data
+for i in range(NUM_RECORDS):
+    conn.execute("""
+        INSERT INTO candidates (id, session_id, status, importance, target_dir, title, content, source)
+        VALUES (?, ?, 'pending', 10, 'Ideas', ?, ?, ?)
+    """, (f"id_{i}", "sess_1", f"Title {i}", f"Content {i}", f"source_{i}"))
+conn.commit()
+
+# Test performance
+import scripts.harvest as harvest
+
+# Override limit in promote_l1 so we test 500 records
+original_promote_l1 = harvest.promote_l1
+
+def patch_promote_l1(vault, conn, threshold=10):
+    rows = conn.execute("""
+        SELECT * FROM candidates
+        WHERE status='pending' AND importance >= ? AND target_dir='Ideas'
+        ORDER BY importance DESC LIMIT ?
+    """, (threshold, NUM_RECORDS)).fetchall()
+    count = 0
+    updates = []
+    for row in rows:
+        try:
+            title = row["title"] or harvest.extract_title(row["content"]) or "Untitled Idea"
+            path = harvest.create_note(vault, "Ideas", title, row["content"],
+                               tags=["#idea", "#auto"], source=row["source"])
+            updates.append((str(path), row["id"]))
+            count += 1
+        except Exception as e:
+            harvest.warn(f"L1 promote error: {e}")
+    if updates:
+        conn.executemany(
+            "UPDATE candidates SET status='promoted', vault_path=? WHERE id=?",
+            updates
+        )
+        conn.commit()
+    return count
+
+start_time = time.time()
+patch_promote_l1(vault_dir, conn, threshold=5)
+end_time = time.time()
+
+print(f"Time taken (executemany + single commit) for {NUM_RECORDS} records: {end_time - start_time:.4f} seconds")
+
+# Cleanup
+conn.close()
+import shutil
+shutil.rmtree(vault_dir)
diff --git a/scripts/harvest.py b/scripts/harvest.py
index e31fdf6..d2086b7 100755
--- a/scripts/harvest.py
+++ b/scripts/harvest.py
@@ -913,21 +913,21 @@ def cmd_flush(vault: pathlib.Path, conn: sqlite3.Connection,
     # L3: auto-draft Reference notes instead of just flagging
     l3_drafted = 0
     l3_lines = []
-    updates = []
+    l3_updates = []
     for r in l3_rows:
         ref_path = create_reference_from_candidate(vault, r)
         title = r["title"] or "untitled"
         if ref_path:
-            updates.append((str(ref_path), r["id"]))
+            l3_updates.append((str(ref_path), r["id"]))
             l3_drafted += 1
             l3_lines.append(f"  - [[References/{ref_path.stem}]] (score {r['importance']})")
         else:
             l3_lines.append(f"  - [ ] **{title}** (score {r['importance']}) — draft manually")
 
-    if updates:
+    if l3_updates:
         conn.executemany(
             "UPDATE candidates SET status='promoted', vault_path=? WHERE id=?",
-            updates,
+            l3_updates,
         )
         conn.commit()