Method truncate_table

sql/sql_truncate.cc:445–583

*/

bool Sql_cmd_truncate_table::truncate_table(THD *thd, TABLE_LIST *table_ref)
{
  int error;
  bool binlog_stmt;
  DBUG_ENTER("Sql_cmd_truncate_table::truncate_table");

  DBUG_ASSERT((!table_ref->table) ||
              (table_ref->table && table_ref->table->s));

  /* Initialize, or reinitialize in case of reexecution (SP). */
  m_ticket_downgrade= NULL;

  /* If it is a temporary table, no need to take locks. */
  if (is_temporary_table(table_ref))
  {
    /*
      In RBR, the statement is not binlogged if the table is temporary or
      table is not up to date in binlog.
    */
    binlog_stmt= (!thd->is_binlog_format_row() &&
                  table_ref->table->s->using_binlog());

    thd->close_unused_temporary_table_instances(table_ref);

    error= handler_truncate(thd, table_ref, TRUE);

    /*
      No need to invalidate the query cache, queries with temporary
      tables are not in the cache. No need to write to the binary
      log a failed row-by-row delete even if under RBR as the table
      might not exist on the slave.
    */
  }
  else /* It's not a temporary table. */
  {
    bool hton_can_recreate;

#ifdef WITH_WSREP
    if (WSREP(thd) && wsrep_thd_is_local(thd))
    {
      wsrep::key_array keys;
      /* Do not start TOI if table is not found */
      if (!wsrep_append_fk_parent_table(thd, table_ref, &keys))
      {
        if (keys.empty())
        {
          if (wsrep_to_isolation_begin(thd, table_ref->db.str, table_ref->table_name.str, NULL))
            DBUG_RETURN(TRUE);
        }
        else
        {
          if (wsrep_to_isolation_begin(thd, NULL, NULL, table_ref, NULL, &keys))
            DBUG_RETURN(TRUE);
        }
      }
    }
#endif /* WITH_WSREP */