Lookups in Oracle

Lookups in Oracle are a collection of values. Lookups are a static collection of codes which are used by oracle for working.

For Example in a form/table if there is a field for Gender rather than storing the values , Male/Female/Unknown the system may prefer to store codes M/F/U . Thus when storing the values rather than storing the description oracle will store the codes M/F/U and display the complete menaning to the user.

Each lookup when defined will have a lookup code and a corresponding meaning for that code. Oracle will internally use codes for working and use meaning when communicating to the user.

Lookup codes are mainly used when working with forms and handling data in the tables.

When ever a lookup is created and entry will be created in the table FND_LOOKUP_TYPES ,

For each lookup type when the value is entered for the lookup entries will be created in the table FND_LOOKUP_VALUES

For the lookups already defined in Oracle each is associated with an application , thus when searching for application specific lookups user should search with the specific application.

Lookups in Oracle are of 3 types:

1. System: These are lookups which are used internally by the system. Users can see and use the lookup but they cannot disable the existing values or add new values.
2. Extensible : These are system provided lookups. Users can add their values if they want , but Seeded values by Oracle cannot be changed 
3. User Defined : User Defined lookups are client specific which are created to meet the business specific customization's. These are created by the users and the users can add new values and disable the older ones.