was available. SMS allows the separation of performance and service level of data sets by use of the Storage Class.

A Storage Class construct details the intended performance characteristics required for a data set assigned to a given class. The response times set for each Storage Class are target response times for the disk controller to achieve when processing an I/O request. It decides if the volume should be chosen by the user or by SMS. Also, it determines whether SMS, when allocating space on the first volume of a multi-volume data set, should allocate space on the remaining volumes as well. The assignment of a Storage Class does not guarantee its performance objective, but SMS selects a volume that offers performance as close as possible. Only SMS managed data sets use Storage Classes. Changes in a Storage Class applies to the data sets that are already using that class.

Storage Classes can be assigned implicitly through the ACS routines, or explicitly by using the following:

•JCL statement. The user only needs to specify the relevant Data Class keyword, such as STORCLAS=SCDBGS.

•DSS COPY and RESTORE commands.

•TSO/E ALLOCATE command such as STORCLAS(SCDBGS).

•IDCAMS ALLOCATE and DEFINE commands.

•ISPF/PDF data set allocation panel.

Unlike the Data Class, users cannot override individual attribute values when allocating data sets.

5.3.2.2 Planning for Implementation

For each group of data sets that have similar performance objectives, a Storage Class can exist. To identify and reference a particular Storage Class, a unique one to eight character name is used, for example, SCDBFAST.

Consideration needs to be given as to whether a user is authorized to select a specific volume within a Storage Group, which is governed by the Guaranteed Space parameter. This is an arrangement which needs to be agreed upon between the storage administrator and the DBA.

An example of the use of this parameter is in the allocation of the Active logs and BSDS, where these data sets have critical performance and availability requirements. The DBA should be allowed to allocate them on specific volumes, which is especially important for dual logging capability, to ensure that the logs are allocated on separate volumes. After being defined, these data sets are rarely redefined.

Table 9 on page 40 provides a list of attributes for consideration.

Table 9. Storage Class Attributes

ATTRIBUTE

COMMENT

 

 

Performance objectives

- Direct bias

 

- Direct millisecond response

 

- Initial access response

 

- Sequential millisecond response

 

- Sustained data rate

 

 

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IBM 5655-DB2, 5695-DF1 manual Storage Class Attributes
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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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