canonical

app/mapper.py

@@ -131,9 +131,11 @@ def _fallback_detection(org_id: str, source_id: str) -> dict:
     
     conn = get_conn(org_id)
     rows = conn.execute("""
-        SELECT row_data FROM main.raw_rows 
-        ORDER BY _ingested_at DESC LIMIT 500
-    """).fetchall()
+            SELECT row_data
+            FROM main.raw_rows
+            WHERE row_data IS NOT NULL
+            USING SAMPLE 100
+        """).fetchall()
     
     if not rows:
         print(f"[fallback] ❌ No data found, returning UNKNOWN")