Many IT organizations leverage Oracle as the online transaction processing (OLTP) database standard. Some may also initially try to leverage the same technology as their decision support platform but find that, for numerous reasons, it does not meet their business and technical needs.

enlarge Various processes are available to meet a multitude of different business and technical needs.

When searching for alternative platforms, companies that find the answer in Teradata can smoothly make the transition to the new platform using the Oracle-to-Teradata migration program. Teradata Professional Services has developed the tools, resources and training that have helped nearly 200 companies migrate, and in doing so Teradata Professional Services has become expert in making the migration process quick and easy. With its presence in the market for more than 10 years through numerous Oracle DBMS version upgrades, the program has evolved to precisely fit customers' needs.

From one to another
Companies choose to migrate from Oracle to Teradata for numerous business and technical reasons.

Today's senior-level executives demand that data warehousing provides both a macro- and micro-level view of the organization. That can be extremely challenging in a company in which data integrity is often an issue as a result of a data warehouse environment composed of multiple data marts. To compound the problem, the more data marts that exist, the more likely it is that there will be conflicting data.

Departmental views are helpful and necessary, but if they conflict with other departments or if senior executives cannot get the answers they need, then those views may cause more harm than good. Enabling management to have a complete view of the business has become a critical component of any data warehousing effort. Many customers have turned to Teradata to provide their organizations with the single view of the business that they have been lacking.

Companies have also found that the data mart strategy—maintaining multiple data marts within an organization—burdens IT departments and data warehousing efforts with heavy, unnecessary costs. Even in modest data warehousing efforts with few data marts, the expense of running and maintaining a competitive platform is significantly more costly than leveraging a comparable Teradata system.

Although there may not be a savings on the up-front expense of setting up an individual data mart or warehouse, the Teradata data warehouse can lessen the ongoing expenditures of annual maintenance, upkeep and cumulative infrastructure cost across the numerous data marts.

To estimate just how much savings might be realized, Teradata uses a time-proven business impact modeling method to accurately compute the cost takeout. With this calculation, organizations can look at hard numbers and see that, by consolidating their data marts onto a single Teradata platform, they gain not only a single view of the business but also real cost savings.

The increased power and flexibility of a Teradata data warehouse also allow businesses to drive deeper for faster insight into their data.

In Teradata's 2006 executive survey, 45% of respondents said decisions are becoming more complex, 68% said the number of daily decisions has increased over the last year, and 85% agreed that decision makers need more up-to-date information than in the past. Clearly, market demands on data warehousing are rapidly evolving and driving the need for faster and deeper insight into that data.

More real-time data analysis and enterprise analytics are becoming necessities, while the need to accommodate mixed workloads is becoming more common. Companies realize that both their business and technical needs must be met in a data warehousing system.

Tools for the trade
The Oracle-to-Teradata migration program comprises processes, tools, professional services and customer training that enable companies to rapidly and efficiently make the transition.

This migration process can take different forms requiring various methodologies and tools:

	Re-hosting one or more data marts into a common database platform or an enterprise data warehouse (EDW)
	Moving an existing EDW to a Teradata platform
	Transforming an operational data store integration into the EDW platform
	Conducting an extended data mart consolidation into an existing Teradata EDW

In the migration process, Teradata first maps the business and technical goals of the company to determine the correct approach from the options shown graphically in the figure above and described below:

	1:1 Migration entails moving the existing data model and schema directly onto the Teradata platform. Little to no change is made to the data model, yet the result is increased performance, availability and scalability, and a decrease in the platform cost of ownership.
	Redesign moves the data model to a normalized model to reduce overall complexity and increase data warehouse flexibility.
	Evolution enables companies to initially maintain their existing data models and move to a flexible normalized model over time.

Once the plan for migration has been established, a number of tools complete the migration process. First the amount of human hours needed to complete the project is accurately estimated. After this step is complete, other tools are used in the actual migration process:

	Ora2TD moves the data from the Oracle database to the Teradata Database. The tool automatically handles all of the data-type conversions, such as number and date, that are necessary. This tool works well with high-volume conversions and can manipulate thousands of tables and millions of rows of data.
	OLE DB Access Module is the sister tool to the Ora2TD with a simple-to-use graphical user interface. This tool works well for low-volume conversions and a small number of tables.
	Automated Application Migration Tool (AAMT) is a translation tool that reads Oracle SQL and proprietary stored procedural language (PL/SQL) and produces executable ANSI/Teradata SQL. The AAMT can translate Oracle SQLPlus scripts to BTEQ scripts and can work with the scripts that contain a mixture of SQL (data definition language and data manipulation language) and PL/SQL. It can translate Oracle built-in SQL functions to Teradata functions, as well as change Oracle cursor-based processing into higher performing SET-based processing. Because of the widespread use of PL/SQL in Oracle data warehousing environments, AAMT is invaluable in enabling rapid migration.

Building knowledge
For a successful migration to a new platform, ongoing service and the right skills must complement the procedure.

A key component of the Oracle-to-Teradata migration program is the educational opportunities specifically tailored toward an Oracle DBA. The specialized coursework enables an Oracle DBA to learn Teradata from an Oracle perspective and rapidly come up to speed on the new platform. This often translates into an Oracle DBA unlearning Oracle-specific tasks (data file management, storage subsystem management, extensive index management, etc.) as opposed to learning a large amount of new Teradata tasks.

Transferring data from one system with multiple data marts into an EDW need not be a complicated, cumbersome endeavor. Through the Teradata Professional Services tools provided by the Oracle-to-Teradata migration program, customers can effectively and speedily move their data from a system that no longer meets their needs to one that is flexible and scalable.

Moving to Teradata provides a powerful technical solution, with benefits including third normal form physical data model support in an analytical environment; unsurpassed linear scalability; and mixed workload capability (enabling both short tactical, as well as larger strategic queries to execute in conjunction with active data loads and event processing) on the same data sets on the same platform at the same time. None of these benefits is possible on Oracle.

Migrating to Teradata provides a strong business solution, as well, by putting companies in the position to enable active enterprise intelligence. This capability allows organizations to view their business from a single integrated EDW platform. T

Mark Shainman, a senior program manager for Teradata, works on the company's strategy, market analysis and master data management teams.

Teradata Magazine-December 2007