# About Container Managed Persistence

Oracle8i manages EJB Entity bean persistence using database tables. Each instance of an entity bean corresponds to a row in the table, and each CMP field corresponds to a column in the table. An Entity bean class also needs a primary key, corresponding to one or more columns of the table, that allow instances to be retrieved using the `findByPrimaryKey()` method.

Corresponding to the tables are two Business Components for Java components:

- An EJB/8i deployment object, which is very similar to a standard Entity Object and stands for the table that manages persistence
- A view object which selects the relevant columns of the table and aliases them to the EJB fields

CMP beans can also make use of other business components classes: domains that allow EJB fields to be based on Oracle object types and secondary view objects corresponding to EJB finder methods.