diff --git a/app/controllers/problems_controller.rb b/app/controllers/problems_controller.rb
--- a/app/controllers/problems_controller.rb
+++ b/app/controllers/problems_controller.rb
@@ -147,10 +147,14 @@
   end
 
   def import
+    @allow_test_pair_import = allow_test_pair_import?
   end
 
   def do_import
     old_problem = Problem.find_by_name(params[:name])
+    if !allow_test_pair_import? and params.has_key? :import_to_db
+      params.delete :import_to_db
+    end
     @problem, import_log = Problem.create_from_import_form_params(params,
                                                                   old_problem)
 
@@ -167,6 +171,14 @@
   ##################################
   protected
 
+  def allow_test_pair_import?
+    if defined? ALLOW_TEST_PAIR_IMPORT
+      return ALLOW_TEST_PAIR_IMPORT
+    else
+      return false
+    end
+  end
+
   def change_date_added
     problems = get_problems_from_params
     year = params[:date_added][:year].to_i
diff --git a/app/views/problems/import.html.haml b/app/views/problems/import.html.haml
--- a/app/views/problems/import.html.haml
+++ b/app/views/problems/import.html.haml
@@ -33,11 +33,12 @@
             %br/
             You may put task description in *.html for raw html
             and *.md or *.markdown for markdown.
-      %tr
-        %td
-        %td
-          = check_box_tag 'import_to_db'
-          Import test data to database (for a test-pair task)
+      - if @allow_test_pair_import
+        %tr
+          %td
+          %td
+            = check_box_tag 'import_to_db'
+            Import test data to database (for a test-pair task)
       %tr
         %td Time limit:
         %td
diff --git a/config/environment.rb.SAMPLE b/config/environment.rb.SAMPLE
--- a/config/environment.rb.SAMPLE
+++ b/config/environment.rb.SAMPLE
@@ -90,8 +90,9 @@
 # TODO: change this to where results are kept.
 GRADING_RESULT_DIR = 'RESULT-DIR'
 
-# Uncomment so that configuration is read only once when the server is loaded
-# Configuration.enable_caching
+# Change this to allow importing testdata into database as test-pairs.
+# This is mainly for Code Jom contest.
+ALLOW_TEST_PAIR_IMPORT = false
 
 # Uncomment so that the system validates user e-mails
 # VALIDATE_USER_EMAILS = true
@@ -99,3 +100,6 @@
 # Uncomment so that Apache X-Sendfile is used when delivering files
 # (e.g., in /tasks/view).
 # USE_APACHE_XSENDFILE = true
+
+# Uncomment so that configuration is read only once when the server is loaded
+# Configuration.enable_caching