> > >maybe this is a silly question but how useful it is to create indexes on > >>columns containing only values 0 and 1 (true and false)? > > > > Perhaps, instead of the index, you might revise your schema a bit. > > > > Why do you have this boolean column? What are you trying to > > achieve? > > > > > I use boolean columns as a flags mostly to mark records as 'exported'. For > example I have table 'Transactions' and I have to export data for some of > our customers (never for all of them).
Right. Flags. IMO, flags are bad. And, as you noticed, it will slow down any queries because a flag cannot be indexed properly. Instead, why create a table Transactions_Exported TransactionID <primary key> This can be indexed and will be fast if you want to get info about any exported transactions. With regards, Martijn Tonies Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL Server Upscene Productions http://www.upscene.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
