what I'm not clear about is when to completely remove a particular index please?
That'll depend on the usage patterns of the particular database and table. If it's a table that's only used for month end reports, you shouldn't go dropping indexes if they haven't been used for two weeks. On the other hand, if it's your main order details table then you'll probably know much sooner that an index isn't of any use.
John
The database is used for one of the main applications and not for reporting, so are you saying that I'm looking at the correct columns before there are up to 50 columns with the value of 0 for the mentioned columns apart from the User update column.