Databases and Deep Copy

Question

If I want to make a deep copy of an object stored in my relational database, should I do something fundamentally wrong in the architecture? This is a different approach to another (much more detailed) question that I asked, but did not get a big answer to the call Copy data from a relational table .

Answer 1

It depends on what your relational tables are, and which of your entities are grouped together to create a "business object." For example, if you have a relational model of a content management system with a Posting table and a Text_lines table, where each posting consists of a list of text strings, a valid copy of your Posting business object is likely to be a deep copy of the Posting entity "along with the owned Text_lines objects.

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Answer 2

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Answer 3

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Answer 4

I believe that if you need a stable clone of a database object, it is best to do a deep copy - at least copy all those elements that may change at some point in the future. I don’t see that there are many alternatives besides introducing some kind of clone copy-to-write style, which, although it may be right in some cases, will lead to a whole host of additional logic and complexity.