Merge mysql.com:/home/mydev/mysql-4.1

    start_bulk_insert(rows)

    rows        Rows to be inserted

                0 if we don't know

  NOTICE

    Do not forget to call end_bulk_insert() later!

*/

void ha_myisam::start_bulk_insert(ha_rows rows)

{

  DBUG_ENTER("ha_myisam::start_bulk_insert");

  THD *thd=current_thd;

  ulong size= min(thd->variables.read_buff_size, table->avg_row_length*rows);

  DBUG_PRINT("info",("start_bulk_insert: rows %lu size %lu",

                     (ulong) rows, size));

  /* don't enable row cache if too few rows */

  if (!rows && rows >  MI_MIN_ROWS_TO_USE_WRITE_CACHE)

  if (! rows || (rows > MI_MIN_ROWS_TO_USE_WRITE_CACHE))

    mi_extra(file, HA_EXTRA_WRITE_CACHE, (void*) &size);

  can_enable_indexes= (file->s->state.key_map ==

      mi_init_bulk_insert(file, thd->variables.bulk_insert_buff_size, rows);

    }

  }

  DBUG_VOID_RETURN;

}

/*

  end special bulk-insert optimizations,

  which have been activated by start_bulk_insert().

  SYNOPSIS

    end_bulk_insert()

    no arguments

  RETURN

    0     OK

    != 0  Error

*/

int ha_myisam::end_bulk_insert()

{

  mi_end_bulk_insert(file);