EAV, or entry-attribute-value model, is known as open schema with better extensibility than row model by which data type of value columns are required to be pre-defined.  On the other hand, row modeling provides easy manipulation with, likely, better performance.

In legacy Xoops, configuration data  model (“config”) is defined with EAV model while user data model (“users”) with row model.

In Xoops Engine, configuration table is modeled with EAV, while user model design is kind of complex in Xoops Engine. Considering performance, data integrity, easy manipulation, user model is defined as three part:

• `user_account`[row model]: id, identity, credential, salt, email, active
• `user_meta`[EAV]: id, key, category, title, …
• `user_profile`: row model with columns generated by `user_meta`
• `user_preference`: assumed to be EAV, not implemented yet considering design complexity

More details coming soon …

原文:http://dev.xoopsengine.org/?p=12