Oracle eBS 11i Infrastructure
In this article we will describe the infrastructure of Oracle eBusiness Suite (eBS). In its simplest form, eBS is a 3-tier application with a client tier, Application-tier and DB-tier.
Let’s start with the DB-Tier. Surprisingly, the database tier has only very little eBS specific features.
Of course we need a database (instance) and therefore an ORACLE_HOME. But the database can either be a single-instance or a RAC-installation and all Oracle RDBMS features are transparently available for eBS.
The management of the RDBMS Installation is also independent of eBS.
Let’s start with the filesystem on the DB-Tier. Of course there is an Oracle_home installation needed, for the RDBMS-Instance. This will be installed during installation of eBS. But also a fresh installed ORACLE_HOME can be used, with an eBS database.
In the ORACLE_HOME, an extra directory is added. The Appsutil directory. This directory contains the software and data needed for running Autoconfig and Rapidclone.
All other directories are at the discretion of the eBS DBA.
When we look at the instance to run eBS, we find a number of mandatory parameters for eBS. These are found in Metalink notes 216205.1 and 396009.1 (At the time of writing. Please verify these notes for yourself).
These parameters are recommended or mandatory based on testing by Oracle Corp. They will automatically be set by the eBS installer. But you should take note of them when you use a fresh installed ORACLE_HOME.
Then we finally come to the contents of the database.
The eBS Database
Let’s start with the schemas in the database. Oracle eBS creates a separate schema for every module. The schema is named as the short_name of the module, for example AP (Oracle Payables / Accounts Payable), AR (Oracle Receivables / Oracle Receivables).
There is a separate schema for the Application owner APPS.
The Application schemas contain the tables, indexes and sequences for the different applications. All objects in these schemas (except indexes, of course) have a synonym in the APPS Schema. In the APPS Schema we also find all PL/SQL objects, views and Materialized Views.
A major part of eBS is written in PL/SQL. All PL/SQL objects are also installed in the APPS Schema.
User sessions within eBS will usually run in the APPS Schema as well.
That brings us to an extra schema in the database: APPLSYSPUB. This schema has access to some of the eBS tables and packages, that allow it to validate eBS logins and start an APPS-session based on that login information. We will see the details of this later on.
Before release 11.5.2 every schema had its own tablespace. However, the number of modules for eBS (and with that the number of schemas) is ever increasing. So managing the database became more and more complex. In 11.5.2 Oracle introduced the Oracle Applications Tablespace Model (OATM). Within this model, the tablespaces in eBS are based on functionality, rather than schemas.
In this model, we see the following tablespaces:
APPS_TS_TX_DATA – Containing all transaction tables, Materialized Views and IOT’s
APPS_TS_TX_IDX – Containing all indexes for transaction tables
APPS_TS_SEED – Containing the tables and indexes with seeded data (as opposed to transaction data).
APPS_TS_INTERFACE – For Open Interface tables
APPS_TS_SUMMARY – Contains summary tables for several modules (AR, PA, BIM, etc)
APPS_TS_NOLOGGING – For tables and objects that are created with the NOLOGGING option
APPS_TS_ARCHIVE – Containing archive and history tables (and indexes)
APPS_TS_QUEUES – Containing the AQ (Advanced Queuing) objects
APPS_TS_MEDIA – Containing tables with LOB’s. For media objects or documents.
The Undo and Temp tablespaces are not part of the tablespace model.
Now it’s time to look at the Application Tier. In fact the Application Tier consists of 3 different services: Web service, Forms service and Concurrent Processing. In 11i installations, there is also an Administration service.
The Application Tier significantly changed from R11i to R12. We’ll discuss the 11i Apps Tier shortly, and then discuss the R12 tier in more detail.
The 11i infrastructure
Both the R11 and R12 infrastructure consist of a Web-service, a Forms Service and a Concurrent Processing part.
We will be discussing the different services here. The following picture shows all components and their communications. You might want to keep it for reference during this article.