DB2 10 for z/OS: Cost Savings . . . Right Out of the Box
104
DB2 10 for z/OS: Cost Savings . . . Right Out of the Box
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Product Details
| ISBN-13: | 9781583476789 |
|---|---|
| Publisher: | Mc Press |
| Publication date: | 03/01/2012 |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 104 |
| File size: | 921 KB |
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DB2 10 for z/OS
Cost Savings ... Right Out of the Box
By Dave Beulke, Roger Miller, Surekha Parekh, Julian Stuhler
MC Press
Copyright © 2010 IBM CorporationAll rights reserved.
ISBN: 978-1-58347-678-9
CHAPTER 1
DB2 10 for z/OS: A Smarter Database for a Smarter Planet™
by Julian Stuhler
Executive Summary
DB2 10 for z/OS is the latest release of IBM's flagship database. The following sections provide a high-level overview of the major new features from an IT executive's perspective, with the emphasis on the underlying business value that DB2 10 can deliver.
DB2 10 delivers a number of significant business benefits, many of which are exploitable "out of the box" with little or no database, application, or system changes. These can be summarized as follows:
• CPU reductions. DB2 includes a raft of enhancements aimed at improving application performance and reducing CPU usage. Most customers can expect to see net CPU savings of 5 to 10 percent in their traditional DB2 workload compared with DB2 9, without any application changes being required. Significant additional savings are possible for other specific workloads, and with some application changes.
• Scalability improvements. DB2 10 delivers a spectacular increase in the number of threads that can be supported by a single subsystem — most customers will be able to achieve 5 to 10 times the number of concurrent connections compared with DB2 9. This will allow many customers to reduce the number of DB2 members needed to support their workloads, resulting in net CPU and memory savings and improving application performance.
• Productivity enhancements. New features such as temporal tables, automated statistics, and improved dynamic schema change reduce the effort required by developers and support staff to deliver robust DB2 applications.
Even in the most favorable economic climate, businesses need to control costs and increase efficiency in order to improve their bottom line. In today's more challenging business environment, this has become a key factor for the survival and success of enterprises of all sizes.
DB2 10 delivers significant "out of the box" benefits that many customers will be able to exploit with little or no additional effort. These include the most aggressive performance and CPU improvements of any DB2 release in the past 20 years, scalability enhancements to support ever-increasing workloads, and productivity improvements to allow DB2 developers and support staff to respond more rapidly to the demands of the business.
Collectively, these features deliver real and quantifiable business benefit, and many customers will be considering upgrading to DB2 10 much more quickly than they may have done for previous releases.
Section I
Introduction
You don't have to be an IT professional to see that the world around us is getting smarter. Everywhere you look, our environment is getting more connected and "instrumented," and clever technologies are being adopted to use the resulting real-time data to make things safer, quicker, and greener. While this explosion in machine-generated data is happening, human beings themselves are also generating vastly more content than ever before. Today, people and machines together create new data at an astounding rate: more data will be created over the next four years than in the entire history of the planet.
Building a smarter planet is going to need smarter IT systems, which in turn will depend upon the availability of a robust, efficient, and secure way of storing, retrieving and analyzing this vast amount of data. From banking to transportation to healthcare, DB2 for z/OS sits at the heart of many of the IT systems needed to drive a Smarter Planet and has an important role to play in supporting the transformation.
In the meantime, the global economic climate remains challenging, and DB2 for z/OS customers around the world are still trying to gain competitive advantage by doing more with less: more business insight, more performance, more operational efficiency, more functionality, more productivity with less cost, quicker time to market, and a lower total cost of ownership (TCO).
DB2 10 for z/OS, the latest release of IBM's flagship database, seeks to address these and other challenges. A wealth of material exists on the technical changes within DB2 10, but finding descriptions of how those new features will improve your business results can be a challenge. This paper provide a high-level overview of the major new features from an IT executive's perspective, with the emphasis on the underlying business value that DB2 10 can deliver.
In the meantime, many customers are still running DB2 for z/OS Version 8 (or earlier releases) and need to understand how DB2 9 can help their organization. A brief summary of the business benefits offered by DB2 9 is provided in the Appendix (page 59).
Section II
DB2 10: A Smarter Database
In this section, we take a detailed look at the major features of DB2 10 and the ways many of IBM's most innovative enterprise customers are intending to use them to deliver an enhanced IT service to the business.
Many of these enhancements can be used "out of the box" with little or no effort required to begin exploiting them, reducing the time to value for a DB2 10 upgrade.
This section is organized around the key DB2 10 themes:
• Efficiency: Reducing cost and improving productivity
• Resilience: Improving availability and data security
• Growth: Supporting new and expanding workloads
• Business Analytics: Enhanced query and reporting
Efficiency
Even in the most favorable economic climate, businesses need to control costs and increase efficiency to improve their bottom line. In today's more challenging business environment, this has become a key factor for the survival and success of enterprises of all sizes.
This section examines the major DB2 10 enhancements aimed at improving the efficiency of the IT systems that rely on DB2: a key design objective for the new release. These features can help to reduce ongoing operational costs, improve developer and DBA productivity, and enhance the customer's experience by increasing performance and delivering a more responsive application.
CPU Reductions
Most DB2 for z/OS customers operate on a CPU usage-based charging model, so increases or decreases in the amount of CPU required to run DB2 applications can have a direct and significant impact on overall operational costs. Traditionally, IBM has tried to limit the additional CPU cost of adding new functionality into each release, keeping the net CPU impact below 5 percent.
The move to a 64-bit computing platform in DB2 V8 was an exception to this rule, and it introduced some significant processing overheads that resulted in many customers experiencing net CPU increases of 5 to 10 percent following the upgrade. DB2 9 helped to redress the balance somewhat by delivering modest CPU improvements for many large customers, but IBM was determined to deliver more significant cost reductions in DB2 10.
One of the fundamental design objectives of DB2 10 was to deliver a 5 to 10 percent CPU reduction "out of the box," with little or no change being required to applications and further savings being possible with some database and/or application changes. Figure 1 shows a pictorial representation of the typical CPU decrease seen in each release since V3.
Based on IBM labs tests and some early beta customer experiences, IBM has exceeded this objective and delivered the most aggressive performance and CPU improvements of any DB2 release in the past 20 years. As many of these improvements are down to internal DB2 code optimization and exploitation of the latest System z hardware instructions, most customers can expect to see CPU savings of 5 to 10 percent in their traditional DB2 workload without any application changes being required.
Figure 2 shows the savings relative to DB2 9 that were achieved in internal IBM testing using the standard IBM Relational Warehouse Workload (IRWW). The first column shows a 3.7 percent CPU saving immediately following migration in DB2 10 compatibility mode (CM). The net saving increased to 7.4 percent following a REBIND of the affected packages with the same access path, and this remained the same when the system was placed in new function mode (NFM). Finally, a net saving of 17.4 percent was measured once the packages had been rebound to use the new RELEASE protocols described elsewhere in this document.
Customers running the following types of workload can expect even bigger CPU savings:
• Workloads previously constrained due to a lack of virtual storage in DB2 V8 or 9.
• Distributed applications connecting to DB2 via the DRDA protocol (e.g., SAP).
• Workloads using native SQL stored procedures. Efficiency enhancements with commonly used functions have shown CPU reductions of up to 20 percent during initial IBM labs testing.
• Workloads with heavy concurrent insert activity, especially where rows are inserted sequentially, where savings of 5 to 40 percent have been observed in the labs.
• Complex query workloads, where up to 20 percent CPU reduction has been observed with no change to the access path. Greater savings are possible where a more efficient access path is selected.
All of these figures assume an upgrade from DB2 9 to DB2 10. For those customers considering a move directly from DB2 V8 to DB2 10, the net impact could be even bigger.
Most of the performance measurements available at the time of writing are based on internal IBM lab workloads, but early indications from beta customers show CPU savings in line with the lab tests. The potential CPU savings made possible by DB2 10 are likely to be the single biggest factor in driving customers to upgrade to the new release — especially as many of the savings can be realized very quickly after the upgrade, and with few or no application changes.
Temporal Tables
Many IT systems need to keep some form of historical information in addition to the current status for a given business object. For example, a financial institution may need to retain the previous addresses of a customer, as well as the current one, and may need to know which address applied at any given time. Equally, an insurance company may need to know what level of coverage was in place two months ago when a claim was made. Previously, these kinds of requirements would have required the DBA and application developers to spend valuable time creating and testing the code, as well as associated database design to support the historical perspective while minimizing any performance impact.
The new temporal data support in DB2 10 provides this functionality as part of the core database engine. The DBA indicates which tables/columns require temporal support when they are created, and DB2 maintains the history automatically whenever an update is made to the data. Elegant SQL support lets the developer query the database with an "as of" date, which will return the information that was current at the specified time.
As shown in Figure 3, DB2 maintains a separate "history table" for updated rows in a temporal table. This is completely transparent to the developer, who codes SQL against the main table as usual. When a row is updated (as shown at time T3 in the diagram), DB2 will store a version of the old row in the history table before updating the current row in the main table. Similarly, when a row is deleted, it is first copied to the history table before being removed from the main table. DB2 maintains system timestamps (the SYS_START and SYS_END columns shown) to record the period during which a given version of the row was current.
Finally, the new AS OF clause in SQL SELECT statements lets the developer see the data as it was at a given point of time. In the example, the policy information at time T2 is required, which will return the original address (A3) instead of the current address (A4).
With so many IT systems needing to accommodate a historical perspective and maintain audit logs of changes made to sensitive data, DB2's new temporal support promises to save many hundreds of hours of design, coding, and testing that would otherwise be required to build this function manually for each application. While the benefit for existing applications is limited, this feature promises to deliver major productivity savings for new developments.
Improved Scalability
The valuable scalability enhancements within DB2 10 are described elsewhere in this document. In addition to supporting workload growth and providing more flexibility, these enhancements can deliver some significant performance benefits, as follows:
Reduction in data sharing overhead. The virtual storage constraints within previous releases of DB2 imposed a practical limit of 400 to 500 concurrent active threads within a single DB2 subsystem. As a result, many DB2 data sharing customers were forced to use more DB2 members than otherwise necessary to support their workloads. Although DB2's industry-leading data sharing architecture minimizes the processing overheads, each additional member will impact overall performance and resource usage.
Figure 4 shows a typical scenario for an SAP environment. In this example, a data sharing group consisting of four DB2 members is used to support 1,600 concurrent threads from four SAP application servers.
DB2 10 introduces some dramatic scalability improvements that allow each system to handle five to 10 times the current number threads. This will allow many customers to reduce the number of DB2 members needed to support their workloads, resulting in net CPU and memory savings and improving application performance.
This benefit is illustrated by Figure 5, which shows that the same 1,600-thread workload can be handled by just two DB2 subsystems, with significant scope for additional workload growth. (Initial SAP benchmarks show 2,500 threads per DB2 system is sustainable.) Productivity savings are also possible due to the reduced requirement to closely monitor available storage.
Improved dynamic statement caching. With the growing popularity of running Java and ERP workloads such as SAP on DB2 for z/OS, dynamic SQL is becoming more and more prevalent. DB2 allows dynamic SQL statements to be cached in order to avoid most of the overheads usually associated with executing dynamic SQL, but the size of this cache was limited in previous releases due to the same virtual storage constraints described above. This in turn limited the effectiveness of the cache.
The virtual storage constraint relief delivered in DB2 10 will enable most customers to dramatically increase the size of the dynamic statement cache, thereby allowing a greater proportion of their dynamic SQL to be cached and reducing CPU and elapsed times for these queries. Other important enhancements that will improve dynamic statement caching in DB2 10 are described elsewhere in this document.
Together, these scalability enhancements give DB2 customers more flexibility in the way they distribute their workload across the available System z servers, while reducing DB2 CPU usage and improving the performance of key application processes.
New Hash Access Method
Many high-volume OLTP applications need to efficiently access a single row via a fully qualified primary key, but most of the access paths available to DB2 today are optimized for accessing sets of rows. Previously, the most efficient access path for a single-row fetch would have been via a unique index on the table, as shown in Figure 6.
While this access path can be highly efficient if multiple rows need to be accessed sequentially, the overhead of navigating the index structure can be expensive for single-row access. Depending on the size of the data, the preceding example would typically require DB2 to access a total of 4 to 6 pages in the index and table, some of which might also require a physical I/O operation to pull the page into the buffer pool if it isn't already resident.
DB2 10 introduces a completely new access method, known as Hash Access. Where a table has been enabled for Hash Access, the vast majority of requests for a single row using the unique key will be satisfied with a single page access because DB2 will use the key as input to a hashing algorithm that will produce the page number and row offset needed to directly access the given row (Figure 7).
(Continues...)
Excerpted from DB2 10 for z/OS by Dave Beulke, Roger Miller, Surekha Parekh, Julian Stuhler. Copyright © 2010 IBM Corporation. Excerpted by permission of MC Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Table of Contents
About the AuthorsPreface
Why Read This Book?
Introduction
PART I: DB2 10 for z/OS: A Smarter Database for a Smarter Planet Executive Summary
Section I: Introduction
Section II: DB2 10: A Smarter Database
Efficiency
Resilience
Growth
Business Analytics
Section III: Upgrading to DB2 10
Skip Migration DB2 V8 Support
Section IV: DB2 10
Customer Case Studies
Case Study #1: Banco do Brasil
Case Study #2: BMW Group
Section V: Summary
Appendix: DB2 9 Review
Notes
PART II: DB2 10 for z/OS: CPU Savings . . . Right Out of the Box
Executive Summary
Section I: Performance Availability
Many Performance Enhancements
New and Improved Online Schema Changes
INCLUDE Non-Unique Columns Within a Unique Index
New Hash Space and Access Method
DB2 Catalog Enhancements
Section II: Scalability, Simplification, Security
Full 64-bit Runtime Environment Exploited
Plan Stability: Package Preservation
RUNSTATS Improvements and Auto Stats
Improved and Finer-Grained Access Control
Section III: Application Enablement
pureXML Enhancements
Temporal Queries and Their Business Advantages
Timestamp, TIME ZONE, and Other Data Type Enhancements
Access to Currently Committed Data
SQL Compatibility Improvements
Section IV: Data Warehousing
Support for Temporal Tables and Versioning
OLAP Functionality Built Directly into DB2
Advanced Business Analytics
Section V: Reduced Total Cost of Ownership
Useful URLs