Object Relational Impedance Mismatch (ORIM) is also known as paradigm mismatch. It means that Object model and Relational model do not work well with each other.
Relational model or a RDBMS represents data in tabular format like a spreadsheet. Object model or OOPS represents the data as an inter-connected graph of objects.
Mixing these two models leads to various problems. The common name for these issues is Object Relational Impedance Mismatch.Read the full book at www.amazon.com