Another vote for source control. That's the single best approach.
You could look to third party tools. For example, Red Gate Software (my employer) has a tool called SQL Compare [/url]that will let you compare two copies of a database, a database to a backup, a database to a set of scripts, or even a database to source control, or any of the above combined, to find where schema has changed.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
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SQL Server Execution Plans
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