Quick Beginnings for DB2 Extended Enterprise Edition for UNIX

Chapter 2. What's New in DB2 Version 5?

Version 5 of DB2 Universal Database Extended Enterprise Edition is the follow-on product to DB2 Parallel Edition Version 1.2 (which was available on AIX only); it includes all the features and enhancements of DB2 Version 2 and Database Server Version 4, and offers many new features. This section describes some of the major changes for this version, and points you to sources of more information in the DB2 library. The numerous enhancements include:

Exploitation of symmetric multiprocessors (SMP) for improved scalability and performance

DB2 now exploits the ability of an SMP system to share resources across multiple processors, performing your SQL queries more quickly. Commands like load, backup, and restore also take advantage of the multiprocessor environments.

For more information on SMP parallelism, refer to the Administration Guide. Commands are described in more detail in the Command Reference.

New graphical tools on OS/2, Windows 95, and Windows NT that make it easy to install, configure, and administer DB2 databases

From the Control Center, you can accomplish just about any administrative task. You can also use the graphical tools to administer any DB2 server on any of the available platforms. For more details, refer to the online help available with the Control Center.

From the Client Configuration Assistant, you can configure communications for clients to access remote or local DB2 servers. For more details, refer to the online help available with the Client Configuration Assistant.

Comprehensive online help and the Information Center help you easily find the information you need to use DB2.

Extensions to SQL, including support for Online Analytical Processing (OLAP)

With the new CUBE and ROLLUP aggregations, you can now create super groups, like overall total and cross tabulation, for improved online analytical processing. You can also perform outer joins, rename tables, define unique constraints on tables, and create your own table functions. DB2 has refined its authorization support, so you can grant authority at a more granular level; you can also create schemas to grant various attributes and privileges. For more details on these and other new SQL features, refer to the SQL Reference.

Performance, capacity, and memory improvements

DB2 now provides global caching for SQL statements, creating a public repository that improves performance. You can create multiple buffer pools of various sizes to better control the data in memory. Client/server communications are more efficient, crash and roll-forward recovery is faster, and load features numerous performance enhancements. For information on how to exploit these enhancements, refer to the Administration Guide.

Security enhancements, including support for Open Software Foundation's Distributed Computing Environment (DCE)

You can now use the DCE architecture to manage users, passwords, and groups more easily, and authenticate users more securely. DB2 also provides a "Trusted Clients" option so you can choose whether to trust all clients or only those that come from an operating system with inherent security. Security considerations are described more fully in the Administration Guide.

Additional support for communicating with host databases using DB2 Connect and the Distributed Relational Database Architecture (DRDA)

In addition to communicating with host systems using SNA, you can now use TCP/IP to communicate with host systems that support this protocol. (Currently, only DB2 for OS/390 Version 5.1 supports TCP/IP.) In addition, DB2 servers can accept requests from host systems using TCP/IP, allowing you to use your DB2 workstation server as an application server to a host application. On OS/2 and UNIX platforms, you can perform two-phase commits using DB2 Connect and TCP/IP; if you're using SNA, you can invoke a two-phase commit involving both the host and the DB2 server. For more details about connecting to host databases, refer to the DB2 Connect Enterprise Edition Quick Beginnings and the DB2 Connect User's Guide.

Enhancements to application programming for DB2

The DB2 Call Level Interface (DB2 CLI) now reflects the Microsoft Open Database Connectivity 3.0 specifications, allowing you to connect to DB2 databases from ODBC 3.0 applications. Additions to user defined functions (UDFs) include scrollable cursors and the UCT_UNIQUE function to return a unique value to use in a table column. You can also invoke external UDFs that are methods of object linking and embedding (OLE) automation servers. For more details on these and other improvements, refer to the CLI Guide and Reference, Embedded SQL Programming Guide, and the API Reference.

There are many other new features, for example:

• The DB2 Governor which you can use to control application behavior.

• New table space features, such as point-in-time roll-forward recovery and selective restore.

• Improved error messages.

For a comprehensive list of what's new, refer to the Information Center.

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