7.2.3 Storage Group

Because the Storage Class has guaranteed space, the BSDS data sets are allocated on the disk volumes requested by the DB2 administrator. The volumes must belong to the assigned Storage Group (such as: SGDBACTL), and the disk volume must be eligible for SMS. For example, this can be done with the DFSMSdss CONVERT command.

•SGDBACTL for several DB2 susbsystems

•SGDB2PLG for the DB2P subsystem

7.2.4 ACS Example

An example of ACS routines to allocate these SMS classes and Storage Groups for BSDSs is shown in Appendix B, section B.1, “BSDS and Active Logs” on page 185.

7.3 Active Logs

The active log data sets are used for data recovery and ensure data integrity in case of software or hardware errors. Active log data sets record all updates to user and system data. If the active log is not available, DB2 cannot guarantee data integrity.

The active log data sets are open as long as DB2 is active. Active log data sets are reused when the total active log space is used up, but only after the active log to be reused has been copied to an archive log.

Data Organization

The active log data sets are VSAM LDSs. Figure 20 on page 69 shows an example definition of an active log data set.

Performance

For DB2 subsystems with high update transaction rates, the active logs have a very high I/O activity (mainly write I/O). The performance of the active logs has an important impact on the overall DB2 subsystem performance. See 10.4.5, “Improving Log Write Performance” on page 114 and 10.5.1, “Improving Log Read Performance” on page 116 for more information.

Availability

The active log data sets have a very high availability requirement for DB2 data integrity. To ensure this, DB2 optionally supports two copies for each active log data set (dual active logs). Dual active logs are highly recommended for DB2 production environments.

To improve active log availability, RAID disks or disks with dual copy can be considered for the active logs.

Migration

Active log data sets should never be migrated by DFSMShsm.

Backup

Every time an active log data sets is filled, DB2 attempts to create an automatic backup. The backup copies of the active log data sets are the archive log data sets.

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IBM 5655-DB2, 5695-DF1 manual Active Logs, ACS Example, Migration, Backup
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5695-DF1, 5655-DB2 specifications

IBM 5655-DB2 and 5695-DF1 are significant components within the IBM software ecosystem, predominantly focusing on data management and integration solutions. These offerings cater primarily to enterprise environments that require robust database management systems and associated frameworks to maintain and manipulate data efficiently.

IBM 5655-DB2 is a well-known relational database management system (RDBMS) that excels in managing large volumes of structured data. Its architecture is designed to support high availability, scalability, and performance, crucial for businesses operating in today’s data-driven world. Some of its main features include advanced indexing capabilities, support for complex queries, and dynamic workload management. Additionally, it provides strong concurrency controls, which enable multiple users to access and manipulate data simultaneously without compromising data integrity.

One of the key characteristics of DB2 is its support for various data types, including JSON and XML, making it versatile for modern applications that generate data in diverse formats. It also features robust security mechanisms to protect sensitive data, aligning with compliance standards across industries. Integration with analytics tools further allows businesses to derive insights from their data, enhancing decision-making processes.

On the other hand, IBM 5695-DF1, also known as the InfoSphere DataStage, is a powerful data integration tool that facilitates the extraction, transformation, and loading (ETL) of data from various sources to target systems. It empowers organizations to streamline their data flows, ensuring that clean, consistent information is available for analysis and operational use. Key features of 5695-DF1 include a user-friendly graphical interface that enhances developer productivity and a rich set of connectors for numerous data sources, enabling seamless data integration.

DataStage also supports real-time data integration, allowing businesses to keep their data synchronized across multiple platforms. Its parallel processing capabilities dedicatedly optimize performance, enabling organizations to handle vast datasets efficiently. It incorporates data quality tools that help in validating and cleansing data before it is used for decision-making processes.

Both IBM 5655-DB2 and 5695-DF1 are part of a broader strategy to accommodate the evolving landscape of data management. Businesses leverage these technologies to enhance their data architectures, fostering agility and competitive advantage in their respective markets. Their integration capabilities, along with a focus on security and scalability, position them as vital assets in modern enterprise environments. Whether managing critical data within a database or ensuring seamless data flow across systems, these IBM offerings provide a comprehensive approach to handling complex data challenges.
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