How do ODBMSs compare to object-relational mapping products?
A. First, let’s look at the similarities. Object database management system products and most object-relational mapping (OR mapping) products let you program in Java or C++ without the use of a database sublanguage such as embedded SQL, ODBC, or JDBC. That part of the development cost is comparable. The main difference between the two occurs in the use and storage of the data. OR mapping products require you to map the object model to a relational model, which requires additional development and can sometimes be a significant performance hit in production. That’s because the way the data is stored is different from how it is used. The term for translating data from storage format to application format and back is “impedance mismatch.” This may be familiar to you. In situations where high performance on complex data is required, impedance mismatch can create performance problems. Also see Object-relational mapping articles (new window).
