Method delete_from_single_table

sql/sql_delete.cc:387–1148

*/

bool Sql_cmd_delete::delete_from_single_table(THD *thd)
{
  int error;
  int loc_error;
  bool transactional_table;
  bool const_cond;
  bool safe_update;
  bool const_cond_result;
  bool return_error= 0;
  bool binlogged= 0;
  TABLE	*table;
  SQL_SELECT *select= 0;
  SORT_INFO *file_sort= 0;
  READ_RECORD info;
  bool reverse= FALSE;
  bool binlog_is_row;
  killed_state killed_status= NOT_KILLED;
  THD::enum_binlog_query_type query_type= THD::ROW_QUERY_TYPE;
  bool will_batch= FALSE;

  bool has_triggers= false;
  SELECT_LEX_UNIT *unit = &lex->unit;
  SELECT_LEX *select_lex= unit->first_select();
  SELECT_LEX *returning= thd->lex->has_returning() ? thd->lex->returning() : 0;
  TABLE_LIST *const table_list = select_lex->get_table_list();
  ulonglong options= select_lex->options;
  ORDER *order= select_lex->order_list.first;
  COND *conds= select_lex->join->conds;
  ha_rows limit= unit->lim.get_select_limit();
  bool using_limit= limit != HA_POS_ERROR;

  Delete_plan query_plan(thd->mem_root);
  Explain_delete *explain;
  Unique * deltempfile= NULL;
  bool delete_record= false;
  bool delete_while_scanning= table_list->delete_while_scanning;
  bool portion_of_time_through_update;
  /*
    TRUE if we are after the call to
    select_lex->optimize_unflattened_subqueries(true) and before the
    call to select_lex->optimize_unflattened_subqueries(false), to
    ensure a call to
    select_lex->optimize_unflattened_subqueries(false) happens which
    avoid 2nd ps mem leaks when e.g. the first execution produces
    empty result and the second execution produces a non-empty set
  */
  bool optimize_subqueries= FALSE;

  DBUG_ENTER("Sql_cmd_delete::delete_single_table");

  query_plan.index= MAX_KEY;
  query_plan.using_filesort= FALSE;

  THD_STAGE_INFO(thd, stage_init_update);

  const bool delete_history= table_list->vers_conditions.delete_history;
  DBUG_ASSERT(!(delete_history && table_list->period_conditions.is_set()));