Data Model

When we install Oracle Database by default system will creates SYS and SYSTEM schemas. These consist of all Data Dictionary Tables. Like this if we install Oracle Applications System will automatically creates schemas of all Modules (i.e. GL, AR, AP, etc.) with the respective module name as User and Password. Along with these schemas some special Schemas i.e. APPS, APPLSYS, APPLSYSPUB will be created for special purpose.

APPS Schema: It is Public Schema. It consists of a collection of public synonym of all the objects of all the schemas in the Application database. All the Procedures, Functions and Packages created must be stored in this Schema.

APPLSYS Schema: This is a special Schema consists of the files starts with FND, ALR, WF and AD.

APPLSYSPUB Schema: This schema is a collection of public synonyms of all FND Tables, which are used for User verification. This is the Gate Way User ID of Oracle Applications.

Note:

1. When we are changing the APPS Schema password, first we have to change in the backend for both APPS and APPLSYS Schemas.
2. Password for both APPS and APPLSYS should be same.
3. Change the password of both the Schemas in Front-End and Back-End

4. Drop the Concurrent Manager Services and re-create the Concurrent Manager Service with the Password as APPS Password.