By Arsalan Saljoughy bject durability, or persistence , is the term you often hear used in conjunction with the issue of storing objects in databases. Persistence is expected to operate with transactional integrity, and as such it is subject to strict conditions. In contrast, language services offered through standard language libraries and packages are often free from transactional constraints. As we'll see in this article, evidence suggests that simple Java persistence will likely stem from the language itself, while sophisticated database functionality will be offered by database vendors. In the real world, you rarely find an object that lacks relations to other objects.
Objects are components of object models .
The issue of object durability transcends the issue of object model durability and distribution once we make the observation that objects are interconnected by virtue of their relations to one another. The relational approach to data storage tends to aggregate data by type. Rows in a table represent the physical aggregate of objects of the same type on disk. The relationships among objects are then represented by keys that are shared across many tables. Hence, in order to construct an object model, these relationships are constructed from the existing keys at run time in a process referred to as table joins .