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Chapter 4. IBM technologies supporting real-time 219

A Balanced Configuration Unit (BCU) is composed of software and hardware that

IBM has integrated and tested as a pre-configured building block for data

warehousing systems. A single BCU contains a balanced amount of disk,

processing power and memory to optimize cost-effectiveness and throughput. It

is basically used to reduce design time, shorten deployments, and maintain

strong performance ratios as they add building blocks to enlarge BI systems.

The Balanced Configuration Unit (BCU) is a complete solution for building a BI

infrastructure using a modular building block design with a focus on data

warehousing.

The BCU definition consists of:

Unit = Building block or logical entity, This allows ease of expansion for

growth.

Configuration = Design specification using preselected a software package

and hardware platform.

Balanced = Meaning a scalable performance ratio of disk, I/O, memory, CPU

and Network for predicable performance.

4.6.1 Balanced Partition Units

The building blocks of the BCU start with a virtual entity, the BPU (Balanced

Partition Unit). The BPU is one DB2 partition and its related components.

Components refer to the processes and hardware resources that service each

individual partition (BPU) and consist of DB2 agents, memory, and disk. The

BPU is built on specifications that have been developed over time based on

extensive experience and is significantly optimized for data warehousing

workloads. For BCU design purposes the BPU is considered the smallest

element used in sizing a configuration. A BPU is depicted in Figure 4-55.

220 Moving Forward with the On Demand Real-time Enterprise

Figure 4-55 BPU building block

There are five types of Balanced Partition Units and each one configured

uniquely to address a specific purpose.

򐂰 Data BPU: a DB2 database partition dedicated to managing both

non-partitioned table data and multi-partitioned table data within a DPF

environment. In a DB2 DPF environment, there are two basic kinds of data

tables: tables which are partitioned across multiple database partitions, and

tables (typically smaller or more static data sets) that are maintained in a

single tablespace.

򐂰 Coordinator BPU: manages user connections and coordinates queries.

򐂰 Catalog BPU: where the DB2 catalog resides.

򐂰 ETL BPU: Using the Data Warehousing Balanced Configuration Unit design

allows you to achieve a scalable system to support future growth with minimal

effort. An ETL BPU consists of a collection of virtual resources that serve the

functions of a conceptual partition where the ETL processing occurs. It has all

the resources that the ETL requires.

򐂰 Application BPU: a conceptual partition where the application processing

typically occurs, and which has all the resources that the application requires.

An example of an application BPU would be the WebSphere Application

Server running DB2 Alphablox.

Although the catalog, the coordinator, and single partition tables share a single

partition, you need to assess each of these functions separately for sizing the

CPU

I/O Channels

BPU

Memory - Bufferpool

Communication

One DB2 Data Partition

DB2 Agents

Storage Capacity

Chapter 4. IBM technologies supporting real-time 221

system. And, as the data warehouse grows, especially in terms of concurrent

usage, you may find that there is benefit in adding one or more additional

coordinator partitions (nodes). These database functions have been separated

because each handles a different type of work and each may require different

resources or possibly different configurations. So, it is quite useful to consider

these functions independently. Each of these functions could also be supported

by the resources of a DB2 database partition (BPU) dedicated only to the specific

function. Thus the terms Catalog BPU, Coordinator BPU, and Single Partition

Tables BPU”. However, as a default best practice all these functions should

reside within one DB2 database partition and can be referred to as the

Administration BPU. As a result, the administration BPU would generally be on a

separate server and sized differently than the Data BPUs. The administration

server is where Query Patroller (QP) and the QP control tables would be

installed to manage your query workload. QP provides a high value query

governing function, so consideration of QP workloads need to be taken into

account when sizing your system.

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