Go with
PUSH
method which is used by most people, it's nothing but loading reports without db. Here a sample tutorial.
C# Crystal Reports without database[
^]
EDIT
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Your Comment(which has been deleted by you ??? ):
Not data base is huge .your solution is just for practice not for professionals work
No, I disagree. In past, I have used that method on more than couple of projects. Actually one of our clients wanted to switchover to another database(SQL to Oracle), So we choose the
PUSH
method. That project now has around 300+ reports. It's not a easy job to change connection on those reports when client wants to go with some other database. Besides, you won't get issues like Timeout error. There're more things related to this method.