APPS Schema 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.
A given Oracle database can store the objects associated with a single installation of the Oracle E-Business Suite. Generally, product data objects are stored in the associated product schemas, whereas product code objects are all stored in the APPS schema
Each Oracle E-Business Suite product has a default Oracle user ID, with the product abbreviation as both the schema name and password. For example, the default Oracle user ID/password for Oracle General Ledger is GL/GL.
A product’s schema determines the ownership of the product’s data objects, such as sequences, tables, and indexes. If two products are installed under the same schema, that schema owns the data objects for both products.
Since a product’s data objects are created in their own schema (such as the GL schema) but the user accesses all data objects through the APPS schema, appropriate grants and synonyms are required between the APPS schema and the base product schemas.
The APPS schema has access to the complete Oracle E-Business Suite data model. It is analogous to the SYSTEM schema, which has access to the entire database. Oracle Applications responsibilities connect to an APPS schema, and the environment variable FNDNAM is set to the name of the APPS schema.
All data objects for a product are owned by a schema for that product, known as a base product schema. One schema, called APPS, owns all the code objects for the Oracle E-Business Suite, and has access to all data objects. There is one APPS schema for every product installation group.
The following code objects are installed in the APPS schema:
Packages, Procedures, Functions, Triggers, Views, Materialized views, Java classes Queues
The following objects are installed in the base product schemas:
Tables, Sequences, Indexes, Constraints, Queues
In addition, there are grants from the tables and sequences to the APPS schema, as well as synonyms from the APPS schema to those objects.
APPS Schema Benefits :
The APPS schema improves the reliability of and reduces the time needed for installation, upgrade, and patching by eliminating the need for
cross-product grants and synonyms. Utilizing a single schema that has access to all objects eliminates cross-product dependencies, and creates a hub-and-spokes access model rather than a spider’s web.