Clean up the dynamically allocated memory

sql/opt_costmodel.cc

@@ -248,12 +248,12 @@ void Cost_factors::update_cost_factor(uint index, ulonglong ops, double value)
   }
 }
 
-void Cost_factors::add_data(Cost_factors that)
+void Cost_factors::add_data(Cost_factors *that)
 {
   has_unsaved_data= true;
-  global.update_global_factor(that.global);
-  for(engine_factor_map::iterator it= that.engine.begin();
-      it!= that.engine.end(); it++)
+  global.update_global_factor(that->global);
+  for(engine_factor_map::iterator it= that->engine.begin();
+      it!= that->engine.end(); it++)
   {
     engine_factor_map::iterator element= engine.find(it->first);
     if(element != engine.end())

sql/opt_costmodel.h

@@ -158,12 +158,19 @@ class Cost_factors
   void update_cost_factor(uint index, ulonglong total_ops, double value);
 
   /* Add data from another Cost_factors object */
-  void add_data(Cost_factors that);
+  void add_data(Cost_factors *that);
 
   /* Write data to optimizer_cost_factors table */
   void write_to_table();
 
   void cleanup();
+
+  ~Cost_factors()
+  {
+    for(engine_factor_map::iterator it= engine.begin(); it != engine.end(); it++)
+      delete it->second;
+    engine.clear();
+  }
 };
 
 extern Cost_factors cost_factors;

sql/sql_class.cc

@@ -899,7 +899,6 @@ THD::THD()
    wait_for_commit_ptr(0),
     main_da(0, false, false),
    m_stmt_da(&main_da),
-   thd_cost_factors(cost_factors),
    equation_no(0),
    unsaved_cost_factors(false),
    utime_before_query(0)
@@ -1531,7 +1530,7 @@ void THD::cleanup(void)
   if(unsaved_cost_factors)
   {
     mysql_mutex_lock(&cost_factors_lock);
-    cost_factors.add_data(thd_cost_factors);
+    cost_factors.add_data(&thd_cost_factors);
     mysql_mutex_unlock(&cost_factors_lock);
   }