delete_dynamic() takes 0.12% in OLTP RO

-   0.12%  mysqld  mysqld

   - delete_dynamic

      + 23.58% lex_end(LEX*)

      + 13.43% lock_table_names(THD*, DDL_options_st const&, TABLE_LIST*, TABLE_LIST*, unsigned long, unsigned int)

      + 13.25% st_select_lex::cleanup()

      + 8.29% QUICK_RANGE_SELECT::~QUICK_RANGE_SELECT()

      + 7.93% JOIN::destroy()

      + 7.93% THD::end_statement()

      + 5.14% delete_explain_query(LEX*)

      + 4.29% my_hash_free

      + 4.12% Explain_basic_join::~Explain_basic_join()

      + 3.66% Explain_query::~Explain_query()

      + 2.86% dispatch_command(enum_server_command, THD*, char*, unsigned int)

      + 2.67% Explain_table_access::~Explain_table_access()

      + 1.66% QUICK_RANGE_SELECT::~QUICK_RANGE_SELECT()

      + 1.20% Explain_select::replace_table(unsigned int, Explain_table_access*)