Vamshi,
Please give more details when posting questions, like relevant log snippets and commands you used. Without those, it becomes a guessing game.
Which OpenACS did you download from CVS (which release tag)? oacs-4-6? HEAD? What's the CVS command you used (will answer previous question)
"the database error". Which database error? Please post the relevant log snippet before you copied the files and after.
Thanks,
-Roberto