Identity map pattern

This article relies on a single source. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Identity map pattern" – news · newspapers · books · scholar · JSTOR (April 2020) (Learn how and when to remove this message)

In database design, the identity map pattern is a database access design pattern used to improve performance by providing a context-specific, in-memory cache to prevent duplicate retrieval of the same object data from the database.^[1]

If the requested data has already been loaded from the database, the identity map returns the same instance of the already instantiated object, but if it has not been loaded yet, it loads it and stores the new object in the map. In this way, it follows a similar principle to lazy loading.

There are 4 types of identity maps

1. Explicit
2. Generic
3. Session
4. Class

See also

• Active record
• Identity function
• Map (mathematics)
• Lazy loading

References

This computer science article is a stub. You can help Wikipedia by adding missing information.

• v
• t
• e