To update all columns you can click " Refresh all" at the toolbar.
To update a certain column you may "Update Column" menu item from the column popup menu.
To set up automatic columns updating please see"Column Alert and Update Properties"
If a column is being updating then the icon to the left of the column's title will be changed.
This will be a help to know whether the icon is under updating.
To stop the process of updating of a certain column click the right mouse button at the column which is under updating and choose "Stop updating" option from the popup menu.