25.5. Inheritance

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JPA offers `SINGLE_TABLE`, `JOINED`, and `TABLE_PER_CLASS` to deal with inheritance mapping, and each of these strategies has advantages and disadvantages.

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• SINGLE_TABLE performs the best in terms of executed SQL statements. However, you cannot use NOT NULL constraints on the column-level. You can still use triggers and rules to enforce such constraints, but it’s not as straightforward.
• JOINED addresses the data integrity concerns because every subclass is associated with a different table. Polymorphic queries or `@OneToMany base class associations don’t perform very well with this strategy. However, polymorphic @ManyToOne` associations are fine, and they can provide a lot of value.
• TABLE_PER_CLASS should be avoided since it does not render efficient SQL statements. </div> </div>