If there r 2 or more users and both have an open select query on the
same table, is there a way to update the query for user 1 if user 2
makes changes on one of the rows without user 1 unpreparing the query
and opening it again? And if not, how can user 1 be notified that
user 2 has changed a row or added a row in order to do the unprepare
and open.

Does an open select query on a table lead to any network performance
difficultiesL That is, if n users have all queried the same table for
browsing, will there be a net and eventually terminal loss of server
efficiency as n increases? (Browsing only, I am familiar as to the
processes on a server when editing and updating occur).