1. Can I use Copy Database Wizard to upgrade my database from SQL server 2005 to SQL Server 2008?
Sure you can, in fact, this method is better than backup/restore as it allows you to copy related objects external to the database such as logins, sql agent jobs, stored procedures from master database etc.
2. Which is the best method to upgrade, an in-place upgrade or a side-by-side upgrade?
Please refer SQL Server in-place vs side-by-side upgrade for more details.
3. Can I do a cross-platform upgrade? I mean, can I upgrade from a 32 bit instance of SQL Server 2000/2005 to a 64 bit instance?
Yes you can, but only using a side-by-side upgrade. Upgrading from a 32 bit instance of SQL Server 2000/2005 to a 64 bit instance of SQL Server 2008 using in-place upgrade is not supported.
4. We are upgrading from SQL Server 2000/2005 to SQL Server 2008, can we upgrade to a different edition than the one we are currently on?
Yes you can, but only using a side-by-side upgrade. In-place upgrade does not support all the paths between editions, for example you can't upgrade from a standard edition of SQL server 2000/2005 to an enterprise edition of SQL server 2008.
5. Is there a way to find out what issues we are likely to encounter during upgrade?
Yes, use Upgrade Advisor to find out potential blocking issues that you might encounter during the upgrade process. You can download SQL Server 2008 Upgrade Advisor from here. Also, run the Best Practices Analyzer against your legacy instance of SQL Server to find out if there are any bad practices which you can address before the upgrade process. You can download the SQL Server 2005 Best Practices Analyzer here.
6. We are still on SQL Server 7.0. Can we upgrade directly to SQL Server 2008?
Yes you can, using a side-by-side upgrade. If you are doing an-inplace upgrade, you would have to first upgrade to SQL Server 2000 or SQL Server 2005, then upgrade to SQL Server 2008.
7. Can I restore a SQL Server 2008 backup to a SQL Server 2005 server?
You can't restore a backup from a higher version of SQL Server on to a lower version of SQL Server. That being said, you can however, script the definition and data in SQL Server 2008(be sure to select the option Script for SQL Server 2005) and use the script to create your database back on SQL Server 2005.
8. Can I use synchronize database wizard to upgrade an analysis services database from SSAS 2005 to 2008?
No, it is not possible to use the synchronize database wizard to synchronize data between SSAS 2005 and SSAS 2008. You can however, backup the analysis services 2005 database and restore it on SSAS 2008 to accomplish the same thing.
To be continued...