1.2 Gateway Capabilities

Oracle Database Gateway for DRDA enables you to integrate your heterogeneous system into a single, seamless environment.

If data is moved from a DRDA database to an Oracle database, then no changes in application design or function are needed. The gateway handles all differences in both data types and SQL functions between the application and the database. As a result, end users and application programmers are not required to know either the physical location or the storage characteristics of the data.

This transparency not only enables you to integrate heterogeneous data seamlessly, it also simplifies your gateway implementation, application development, and maintenance. These topics explain the gateway capabilities:

• Transparency at All Levels
  Oracle Database Gateway for DRDA gives you transparency.
• Extended Database Services
  This topic describes Oracle database services available through the gateway.
• Extended Advanced Networking, Internet and Intranet Support
  The gateway integration with the Oracle database extends the benefits of the Oracle Internet and Oracle Net software to non-Oracle data and extends the benefits of the Oracle client/server and server/server connectivity software.
• Dynamic Dictionary Mapping
  This topic describes dynamic dictionary mapping.
• SQL
  Oracle Database Gateways ease your application development and maintenance by allowing you to access any data using a uniform set of SQL.
• Data Definition Language
  Oracle Applications can create tables in target data stores by using native data definition language (DDL) statements.
• Data Control Language
  You can issue native data control language (DCL) statements from an Oracle environment, allowing central administration of user privileges and access levels for heterogeneous data stores.
• Passthrough and Native DB2 SQL
  Execution of native DB2 SQL can be passed through the gateway for execution directly against DB2.
• Stored Procedures
  The gateway enables you to exploit both Oracle and non-Oracle stored procedures, leveraging your investments in a distributed, multi-database environment.
• Languages
  Any application or tool that supports the Oracle database can access over thirty different data sources through the Oracle gateways.
• Oracle Database Technology and Tools
  The gateway is integrated into the Oracle database technology, which provides global query optimization, transaction coordination for multi-site transactions, and support for all Oracle Net configurations.
• SQL*Plus
  You can use SQL*Plus for moving data between databases.
• Two-Phase Commit and Multi-Site Transactions
  The gateway can participate as a partner in multi-site transactions and two-phase commit.
• Site Autonomy
  All Oracle database products, including gateways, supply site autonomy.
• Migration and Coexistence
  The integration of a data source through the gateway does not require any changes to be made to applications at the data source. The result is that the Oracle database technology is non-intrusive, providing coexistence and an easy migration path.
• Security
  The gateway does not bypass existing security mechanisms. Gateway security coexists with the security mechanisms already used in the operating environment of the data source.
• DRDA UDB Server Encryption support
  Oracle Database Gateway for DRDA provides complete UDB server Encryption support.

1.2.1 Transparency at All Levels

Oracle Database Gateway for DRDA gives you transparency.

For example:

• Location

  Users can access tables by name and do not need to know the physical location of the tables.

• Network

  The gateway exploits the Oracle Net technology to allow users to access data across multiple networks without concern for the network architecture. TCP/IP protocol is supported. This release supports IPV4 and IPV6 between Oracle database and the gateway, and also between the gateway and the DB2 server.

• Operating System

  Users can access data stored under multiple operating systems without being aware of the operating systems that hold the data.

• Data Storage

  The gateway provides the ability for data to be accessed regardless of the database or file format.

• Access Method

  You can utilize a single dialect of SQL for any data store, eliminating the need to code for database-specific access methods or SQL implementations.

1.2.2 Extended Database Services

This topic describes Oracle database services available through the gateway.

For example:

• SQL functions

  Your application can access all your data using Oracle SQL. The method by which the gateways are integrated with the Oracle database ensures that the latest features of each database release are always available immediately to the gateway.

• Distributed capabilities

  Heterogeneous data can be integrated seamlessly because Oracle distributed capabilities, such as JOIN and UNION, can be applied against non-Oracle data without any special programming or mapping.

• Distributed query optimization

  The Oracle database can utilize its advanced query optimization techniques to ensure that SQL statements are executed efficiently against any of your data. The data distribution and storage characteristics of local and remote data are equally considered.

• Two-phase commit protection

  The Oracle database two-phase commit mechanism provides consistency across data stores by ensuring that a transaction that spans data stores is still treated as a single unit of work. Changes are not committed (or permanently stored) in any data store unless the changes can be committed in all data stores that will be affected.

• Stored procedures and database triggers

  The same Oracle stored procedures and database triggers can be used to access all of your data, thereby ensuring uniform enforcement of your business rules across the enterprise.

1.2.3 Extended Advanced Networking, Internet and Intranet Support

The gateway integration with the Oracle database extends the benefits of the Oracle Internet and Oracle Net software to non-Oracle data and extends the benefits of the Oracle client/server and server/server connectivity software.

These features include:

• Application server support

  Any Internet or intranet application that can access data in the Oracle database can also incorporate information from data stores accessible through the gateways. Web browsers can connect to the Oracle database using any application server product that supports Oracle software.

• Implicit protocol conversion

  Oracle and Oracle Net can work together as a protocol converter, allowing applications to transparently access other data stores on platforms that do not support the clients network protocol. An Oracle database can use TCP/IP to communicate with the gateway and another data store.

• Advanced Security

  Non-Oracle data can be protected from unauthorized access or tampering during transmission to the client. You can do this by using the hardware-independent and protocol-independent encryption and checksum services of Advanced Security.

• Wireless communication

  Oracle Mobile Agents, an Oracle industry-leading mobile technology, enables wireless communication to Oracle database or to any databases that are accessible through the gateways. This gives your field personnel direct access to enterprise data from mobile laptop computers.

1.2.4 Dynamic Dictionary Mapping

This topic describes dynamic dictionary mapping.

The simple setup of the gateway does not require any additional mapping. Before an application can access any information, the application must be told the structure of the data, such as the columns of a table and their lengths. Many products require administrators to manually define that information in a separate data dictionary stored in a hub. Applications then access the information using the hub dictionary instead of the native dictionaries of each database. This approach requires a great deal of manual configuration and maintenance on your part. As administrators, you must update the data dictionary in the hub whenever the structure of a remote table is changed.

Inefficient duplication is not necessary with Oracle Database Gateway for DRDA. The gateway uses the existing native dictionaries of each database. Your applications access data using the dictionaries designed specifically for each database, which means no redundant dictionary ever needs to be created or maintained.

1.2.5 SQL

Oracle Database Gateways ease your application development and maintenance by allowing you to access any data using a uniform set of SQL.

Changes to the location, storage characteristics, or table structure do not require any changes to your applications. ANSI and ISO standard SQL are supported, along with powerful Oracle extensions.

1.2.6 Data Definition Language

Oracle Applications can create tables in target data stores by using native data definition language (DDL) statements.

1.2.7 Data Control Language

You can issue native data control language (DCL) statements from an Oracle environment, allowing central administration of user privileges and access levels for heterogeneous data stores.

1.2.8 Passthrough and Native DB2 SQL

Execution of native DB2 SQL can be passed through the gateway for execution directly against DB2.

This enables applications to send statements, such as a DB2 CREATE TABLE, to the gateway for execution on a target DB2 system.

1.2.9 Stored Procedures

The gateway enables you to exploit both Oracle and non-Oracle stored procedures, leveraging your investments in a distributed, multi-database environment.

Oracle stored procedures can access multiple data stores easily, without any special coding for heterogeneous data access.

Oracle Stored Procedures

Oracle stored procedures enable you to access and update DB2 data using centralized business rules stored in the Oracle database. Using Oracle stored procedures can increase your database performance by minimizing network traffic. Instead of sending individual SQL statements across the network, an application can send a single EXECUTE command to begin an entire PL/SQL routine.

Native DB2 Stored Procedures

The gateway can execute DB2 stored procedures using standard Oracle PL/SQL. The Oracle application executes the DB2 stored procedure as if it were an Oracle remote procedure.

1.2.10 Languages

Any application or tool that supports the Oracle database can access over thirty different data sources through the Oracle gateways.

A wide variety of open system tools from Oracle Corporation and third-party vendors can be used, even if the data is stored in legacy, proprietary formats. Hundreds of tools are supported, including ad hoc query tools, Web browsers, turnkey applications, and application development tools.

1.2.11 Oracle Database Technology and Tools

The gateway is integrated into the Oracle database technology, which provides global query optimization, transaction coordination for multi-site transactions, and support for all Oracle Net configurations.

Tools and applications that support the Oracle database can be used to access heterogeneous data through the gateway.

1.2.12 SQL*Plus

You can use SQL*Plus for moving data between databases.

This product gives you the ability to copy data from your department databases to corporate Oracle database instances.

1.2.13 Two-Phase Commit and Multi-Site Transactions

The gateway can participate as a partner in multi-site transactions and two-phase commit.

How this occurs depends on the capabilities of the underlying data source, meaning that the gateway can be implemented as any one of the following:

• Full two-phase commit partner
• Commit point site
• Single-site update partner
• Read-only partner

The deciding factors for the implementation of the gateway are the locking and transaction-handling capabilities of your target database.

Oracle Database Gateway for DRDA by default is configured as a commit point site, that is, commit confirm protocol. Optionally, you can configure the gateway as read-only if you choose to enforce read-only capability through the gateway. Other protocols are not supported.

1.2.14 Site Autonomy

All Oracle database products, including gateways, supply site autonomy.

For example, administration of a data source remains the responsibility of the original system administrator. Site autonomy also functions such that gateway products do not override the security measures established by the data source or operating environment.

1.2.15 Migration and Coexistence

The integration of a data source through the gateway does not require any changes to be made to applications at the data source. The result is that the Oracle database technology is non-intrusive, providing coexistence and an easy migration path.

1.2.16 Security

The gateway does not bypass existing security mechanisms. Gateway security coexists with the security mechanisms already used in the operating environment of the data source.

Functionally, gateway security is identical to that of an Oracle database, as described in the Oracle Database Security Guide. Oracle database security is mapped to the data dictionary of the data source.

1.2.17 DRDA UDB Server Encryption support

Oracle Database Gateway for DRDA provides complete UDB server Encryption support.