DB2 & IMS

DB2 10 is here, and IT organizations around the world are making plans to migrate to it for a variety of reasons. Let’s look at 10 reasons to move to DB2 10:

10. Improvements to the catalog. Links in the catalog and directory were removed in DB2 10 to reduce lock contention. Improved lock avoidance holds locks for less time, preventing data writers from blocking data readers. The result is improved concurrency.

9. Virtual storage restraint relief. DB2 10 removes virtual storage constraints of individual DB2 subsystems and moves most memory to 64-bit. The benefit is scalability and simplified administration.

8. Hash tables. Some high-volume online applications need to access a single row through a fully qualified primary key. The only way to guarantee this access has been through an index, and indexes require overhead because DB2 must open several pages in the index and table. DB2 10 introduces hash access, which enables access to a single row through a single page. Hash accessed-enabled tables take more disk space than traditional tables and they may be more expensive for multiple row access, but they’re more efficient than indexes for applications that need single-row access.

7. Security and auditing. DB2 10 offers better granularity for managing security. You can manage table access at the column and row levels. You can create multiple audit policies.

6. Online schema evolution. Beginning with DB2 V8, IBM has enabled you to alter database structures dynamically. In DB2 10, you can alter the table space type and convert older table spaces to Universal Table Spaces (UTSs), which can simplify space management and improve availability and productivity.

5. Plan stability, which was introduced as maintenance to DB2 9, is part of the DB2 10 base code. Plan stability makes it safer to rebind static packages after a DB2 upgrade. If performance degrades after a REBIND, you can switch back to the previous access path by running REBIND again with the SWITCH parameter.

4. SQL enhancements. The days of applications and data living solely on the mainframe are limited. IBM recognizes this fact, and has delivered enhancements in DB2 10 that make it easier to port applications from other platforms and database management systems to DB2 for z/OS. Enhancements include faster native SQL procedure language (SQL PL), implicit casting, and more flexibility in the number of digits for fractions of seconds, timestamps with time zones, moving sums, and moving averages.

3. Support for DB2 V8 is ending. Moving to DB2 V8 was a daunting task for many IT organizations because V8 was so different from any previous version of DB2. According to informal polls we’ve conducted, approximately one-third of DB2 users are still on V8 and will move directly to DB2 10. Some users are moving specifically because support for V8 is scheduled to end in April 2012. Whatever the reason for the migration, users will see significant benefits from DB2 10.

2. Temporal tables. DB2 10 supports system time (where DB2 maintains the beginning and ending timestamps for a row) and business time (where you maintain the timestamps). This is especially useful when you need to know the state of the data at a certain time. For example, if you had a car accident last week but didn’t report it until this week, your insurance company would need to know what policy you had at the time of the accident. While they can find that information now through complex application programming, temporal tables will make it much easier. The insurance company can use business time to determine what policy you had at the time of the accident.

1. Performance improvements. When was the last time your manager told you that performance could slip? Chances are, you’re being told to improve performance. It’s easy to do with DB2 10. IBM says that most users can see a 5 to 10 percent performance improvement out-of-the box and up to 20 percent performance improvement for specific workloads. DB2 10 reduces CPU usage with better memory access and shorter processor times, adds more memory, and exploits z/OS enhancements. For optimal performance, you will need to REBIND.

Migrating to DB2 10 is inevitable, and the benefits are real. Work with IBM and your vendors to ensure a smooth migration.