Today�s business environment changes at Internet speed.New technologies and services must be brought online quickly to respond to changing competitive pressures. To keep up with the changes that happen at Internet speed, applications must grow continuously to handle greater load and larger data sets, necessitating changes across all the tiers of Internet application platform. A majority of the changes are needed in the schema objects supporting the application. If administrators cannot respond to the rapid pace of change requests, business productivity can decline.

Oracle Change Management Pack eliminates errors and loss of data when upgrading databases to support new applications. The pack analyzes the complex dependencies associated with application change and automatically performs the required schema upgrades. From a central graphical user interface, users initiate changes safely with easy-to-use wizards that walk users through the steps required for the schema changes. 

Oracle Change Management Pack includes the following features:

• Powerful : With built-in impact analysis, dependency correlation, change deployment and change propagation, database administrators (DBAs) and developers can respond rapidly to new requirements. 

• Easy-To-Use : With a convenient central interface and graphical wizards, implementing complex changes is simple and safe. Complex tasks are reduced to four easy steps. 

• Learn While You Work : With built-in teaching tools, DBAs and developers rapidly expand their knowledge and skills while significantly increasing overall productivity. 

Fig 1 Use Oracle Change Management Pack to easily manage complex changes in the Oracle Platform
 

Four Simple Steps

The components of the Oracle Change Management Pack enable administrators to safely make complex changes to schema objects, track changes to schemas and databases over time, make copies of schemas or objects, and compare and synchronize schemas and databases. These
complex tasks are reduced to four simple steps:

1. Investigating and Tracking Changes
2. Defining and Planning Change
3. Evaluating the Change�s Impact
4. Implementing Change

1. Investigating and tracking changes 

Managing change often involves trying to figure out what changes have taken place in the past. Oracle Change Management Pack makes it easier to investigate past changes by automatically generating Data Definition Language (DDL) for a schema, and by allowing the comparison of databases and schemas.

Capturing  object definitions 

Oracle Change Management Pack records definitions of schema objects, allowing �reverse engineering� of a schema. This is particularly useful when an administrator inherits a schema or application, but not the creation scripts. Oracle Change Management Pack can also archive schema definitions as DDL statements or as baselines. Baselines are internal representations that can be used by other Oracle Change Management Pack tools.
 

Keeping a history of changes 

Oracle Change Management Pack enables DBAs to use baselines to keep track of changes made over time. For example, a baseline can be captured every week for a development schema that changes frequently. Each time a baseline is recaptured, it is labeled with a new version number. Each version can also be separately annotated. Baselines can also be scheduled to be captured on a regular basis or a specified time. In this way, you can use the Oracle Change Management Pack to take regular �meta-data backups�. These baseline versions can be kept as a record or used to return the schema to past states, if needed.
 

Comparing objects and schemas 

Oracle Change Management Pack allows easy comparison of schemas or databases. For example, the schemas of two versions of an application can be compared to identify the customizations done on the older version. A developer can compare a baseline schema with one under development to review the changes made so far. The developer can include the Analyze statistics when comparing schema objects.

Oracle Change Management Pack makes comparisons convenient - administrators or developers can compare one schema or database to another, one schema or database to a baseline, or even the baselines of a schema or database. It also gives you an option to include the database initialization parameters when comparing a database or it's baseline to another. Comparisons can be saved, re-compared to create a new version of the comparison, and scheduled to be run at a particular time. Oracle Change Management Pack can also generate and save a detailed report of the comparison and the differences found.
 

Figure 2. Compare Database and Baseline Object Definitions With Just a Few Mouse Clicks
 

Synchronizing objects and schemas

Once a comparison is made in Oracle Change Management Pack, it can also synchronize the objects compared. For example, an administrator can compare two databases, then use the Synchronization Wizard to synchronize them so their schema definitions are the same. As with all changes made by the Oracle Change Management Pack, the synchronization process generates a script to perform the changes and an impact analysis to examine the changes before they are made.

2. Defining and planning changes

Implementing a change can be as easy as granting a role to a user in Oracle® Enterprise Manager, or as difficult as moving a table from one schema to another, a daunting task requiring administrators to analyze dependencies, move data, and recreate dependent objects. Oracle Change Management Pack makes implementing even complex changes safe and easy.

 Figure 3. Plan Editor Allows You to Specify Sets of Changes to Be Performed

Modifying Schema Objects

Using Oracle Change Management Pack, you can make a single change to one object or multiple changes to multiple objects. These powerful application tools enable administrators to do much more than make simple alterations using SQL statements. Any attribute of a database or schema
object can be changed  - even recreating objects or moving data, such as re-ordering the columns of a table, moving an index to another tablespace, or changing a user name.

3. Evaluating the impact of changes

Before implementing changes, Oracle Change Management Pack analyzes change dependencies and generates an impact report. In many environments, schemas and schema objects have complicated relationships. Many different users might be granted privileges on an object marked for change. Foreign key constraints may reference a column scheduled to be dropped. Triggers, views, or other objects can reference an object selected to be moved to another schema.

Oracle Change Management Pack reports these dependencies before changes are implemented. This allows administrators to anticipate all the effects of a schema change and account for them in change specifications. Oracle Change Management Pack will also anticipate potential errors, such as lack of space or insufficient privileges, so that you can address them before actually implementing the changes. Once changes have been specified, Oracle Change Management Pack generates a script for implementing the changes and analyzes the possible impact the changes may have. This impact analysis is done before the script is executed. This allows the administrator to examine the impact analysis for possible error conditions or undesirable side effects.
 

4. Implementing Change

Many administrators spend a significant amount of time duplicating objects. For example, when a new applications developer starts, the Oracle administrator often needs to create a standard user, schema, and table data for the developer. Oracle Change Management Pack makes it easy to copy objects and schemas. Using Oracle Change Management Pack�s intuitive graphical interface, the administrator can easily specify the objects or schemas to duplicate and their target destinations. Oracle Change Management Pack then creates the script to propagate the objects or schemas and copy the data to each target database.

Oracle Change Management Pack can also propagate changes to existing objects. For example, when upgrading an application, schema changes often need to be propagated to all databases
running that application. Using Oracle Change Management Pack, administrators only need to specify the necessary changes once. Then they can propagate those changes easily to all the required target databases.

Because it is possible that all the targets are not identical, Oracle Change Management Pack will generate the appropriate script for each database to correctly implement the changes. Additionally, Oracle Change Management Pack also allows you to schedule when your changes should be
performed. This allows you the flexibility to schedule changes during off-peak times.

 Figure 4. DB Propagate Allows You to to Propagate db objects after modifying their storage parameters.
 

Cloning application schemas

The Oracle Change Management Pack also makes it easy to clone or propagate application schemas.  You can use the pack to make a "scale-model" copy of a production schema for development or test.  For example, you can scale-back the storage parameters and subset the data copied over.  The Oracle Change Management automatically copies all dependencies and dependent data in the subset so that the result is a working scaled-down version of the application schema.

Keeping a history

When an administrator performs change management tasks using the Oracle Change Management Pack, the work logged and saved is identified as belonging to that administrator. This allows multiple administrators to keep their individual responsibilities separated, if desired. Identifying the tasks that individual administrators have performed also allows others, such as internal auditors, to track who has made specific changes.

Figure 5. Change Management Pack  Allows You to track the change operations
 

Summary 

Responding quickly to changes in an E-business is critical to it's success. Using Oracle Change Management Pack administrators can ensure that changes to the application schemas are made efficiently and without error.