Tài liệu Expert Oracle GoldenGate ppt

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488 CHAPTER 9: Super Jumper: A 2D OpenGL ES Game

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matter material after the index. Please use the Bookmarks

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Contents at a Glance

About the Authors ................................................................................................... xvii

About the Technical Reviewer ............................................................................... xviii

Acknowledgments ................................................................................................... xix

■Chapter 1: Introduction ........................................................................................... 1

■Chapter 2: Installation ............................................................................................. 5

■Chapter 3: Architecture ......................................................................................... 33

■Chapter 4: Basic Replication ................................................................................. 49

■Chapter 5: Advanced Features ............................................................................... 85

■Chapter 6: Heterogeneous Replication ................................................................ 111

■Chapter 7: Tuning ................................................................................................ 127

■Chapter 8: Monitoring Oracle GoldenGate ........................................................... 153

■Chapter 9: Oracle GoldenGate Veridata ............................................................... 171

■Chapter 10: GoldenGate Director ......................................................................... 189

■Chapter 11: Troubleshooting Oracle GoldenGate ................................................ 217

■Chapter 12: Disaster Recovery Replication ......................................................... 241

■Chapter 13: Zero-Downtime Migration Replication ............................................. 263

■Chapter 14: Tips and Tricks ................................................................................. 279

■Appendix: Additional Technical Resources for the

Oracle GoldenGate Administrator ....................................................... 291

Index ....................................................................................................................... 301

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C H A P T E R 1

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Introduction

Oracle Corporation acquired GoldenGate in 2009 as part of future strategy to implement advanced

replication technologies within the product suite of data warehousing and real-time transaction

management. Before the advent of Oracle GoldenGate technology, data replication was performed using

Oracle Streams and third-party replication solutions such as Quest SharePlex. This chapter discusses

various types of database replication methods along with the techniques used by each method, to

illustrate how Oracle GoldenGate came to be the logical conclusion for the current and future real-time￾based data-transaction replication technology with Oracle database systems.

Before the chapter discusses the foundations of Oracle GoldenGate software, a brief history of time

is warranted for how database replication technologies came into existence. Before GoldenGate

software, data transactions were replicated across networks with simple file transfers via the File

Transfer Protocol (FTP) for nonrelational databases. With the popularity of the UNIX operating system

and the advent of client-server computing, data replication was implemented with Oracle basic and

advanced replication software in version 8 of Oracle database software.

Distributed Processing and Replication

Oracle release 5 introduced distributed processing queries in the form of database links. Database links

provided the ability to issue SQL queries across networks and were the first real attempt to achieve a

replication solution. Figure 1-1 shows how connectivity is established between the source and target

database environments via database links.

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Figure 1-1. Database links for distributed systems

The next step in the march of data replication came into existence with Oracle release 8, which

enabled database professionals to set up log-based and trigger-based replication solutions.

Oracle Basic Replication

Oracle basic replication existed in two flavors: log-based and trigger-based. With log-based replication,

you had to set up snapshot schemas and database links between the source and target database

environments. Data was mined from the online redo logs in Oracle to capture the changes and

propagate them across the network to send data transactions from the source database (a.k.a. master) to

the target database. The schemas had be configured on both the source and target databases as well. In

addition, refresh groups had to be configured in order to keep the target environments in sync with the

primary master database on the source system. As you can imagine, the design was crude and prone to

errors in terms of establishing a successful conflict-resolution system of checks and balances.

Oracle Advanced Replication

Oracle advanced replication added more robust features to allow for multimaster replication with

multiple environments, as well as trigger-based methods to establish conflict-resolution rulesets to

improve data reliability and to maintain accurate data synchronization between source and target

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systems. Nonetheless, advanced replication had its shortcomings and flaws, particularly the lack of

support for certain data types and failures that occurred with trigger-based conflict handling. Also,

latency was an issue in terms of keeping the target systems in sync with source master systems.

Figure 1-2 shows how conflict resolution was set up for basic and advanced replication in Oracle

environments.

Figure 1-2. Conflict resolution for Oracle replication

Oracle Streams Replication

Oracle introduced the Streams replication solution in release 9.2. Streams resolved the deficiencies that

plagued the older replication methods in previous releases. It established a log-based replication

solution that mined the online redo logs for committed transactions on the source to move the data to

downstream target systems. In addition, Streams introduced new background processes to maintain the

communication and operations of replication activities within the Oracle ecosystem.

Streams further enhanced previous Oracle replication technologies by using advanced queuing

technology to boost replication performance. Oracle Advanced Queuing (AQ) is a technology designed

with Streams and other Oracle technologies including Oracle Data Guard logical databases. AQ provides

a system of enqueues and dequeues based on the subscriber and publisher model for database

communication. It allows for robust messaging and processing of data transactions between source and

target environments and lies at the heart of Oracle Streams processing.

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Further details on how to set up and manage AQ are available online in the Oracle reference

documentation at http://tahiti.oracle.com.

Evolution and Oracle GoldenGate

With the advent of true log-based replication technology from Oracle and Quest SharePlex, advances

made it possible to finally perform real-time-based replication. Out of the mainframe and midsize

systems world arose a shining star in the development of real-time transaction-based replication

techniques. In the late 1980s, a small software company called GoldenGate came up with a different

method of replicating data between database platforms. Until GoldenGate, replication of data across

platforms and vendors was problematic at best. For example, complex software development was

required to harness the power of Oracle to non-Oracle database environments via the Pro-C and

software development APIs to allow transactions to be moved between environments.

GoldenGate invented a powerful and novel way to replicate data while achieving high performance

with accuracy. Instead of using different formats, GoldenGate implements a uniform format to perform

data replication operations by using a command prompt interface called GoldenGate Software

Command Interface (GGSCI). GGSCI commands are used to create new GoldenGate replication

configurations as well as to perform administration tasks. Committed transactions are stored in flat files

called trail files on the filesystem for both the source and target systems. In addition, GoldenGate

provides a seamless and transparent method to perform real-time data replication with guaranteed

transaction consistency between heterogeneous environments without the need to develop complex

routines or code.

Summary

This introduction has provided a history lesson on how database replication technologies evolved into

the robust Oracle GoldenGate technologies. The next chapter shows you how to install the Oracle

GoldenGate product suite.

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C H A P T E R 2

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Installation

The installation process for Oracle GoldenGate is simple compared to most of the other product suites

available from the Oracle Fusion Middleware family, of which GoldenGate is a part. In this chapter, we

will provide you with details on how to prepare for and perform a complete installation of the following

Oracle GoldenGate products:

• Oracle GoldenGate 11g

• Oracle GoldenGate Director 11g

• Oracle GoldenGate Veridata 11g

Downloading the Software

For Oracle GoldenGate 11g, the first step is to obtain the software either online or from DVD media.

Depending on the bandwidth of your Internet connection, we recommend that current Oracle

customers download the Oracle GoldenGate software from Oracle E-Delivery at http://edelivery.

oracle.com. For educational and non-business learning purposes, Oracle provides the software free for

download from the Oracle Technology Network (OTN) at http://otn.oracle.com. In this chapter, we will

download the Oracle GoldenGate software from http://edelivery.oracle.com.

We recommend that you register for a free account at the OTN site to receive access to free software

for trial purposes, white papers, and webcasts from Oracle. We also advise that you review the

documentation for Oracle GoldenGate online at http://download.oracle.com/docs/cd/E18101_01/

index.htm to become familiar with the particular release notes for your database and operating system

platform. While the primary focus of this chapter will concentrate on Oracle database platform with

GoldenGate, we will provide coverage for additional RDBMS platforms such as MySQL and Teradata in

terms of the installation requirements and guidelines for Oracle GoldenGate.

Downloading from Oracle E-Delivery

Let’s get started and download the Oracle GoldenGate software from edelivery.oracle.com. If you prefer

to download from OTN, then skip ahead to the next section where we show the use of

http://otn.oracle.com.

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Figure 2-1 shows the results from a media search. Choose the platform and version for your

operating system to obtain the Oracle GoldenGate software as shown in the figure. Choose Oracle

Fusion Middleware as your platform. Then specify your operating system.

Figure 2-1. E-Delivery website for obtaining Oracle Goldengate software

Once you have chosen the correct platform, you will see choices for the Oracle GoldenGate software

to download, as shown in Figure 2-2.

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Figure 2-2. Downloading Oracle Goldengate software from E-Delivery

Once you have chosen the correct Oracle Goldengate software—which, in our example, is for the

Windows platform—you will be taken to the download screen shown in Figure 2-3.

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Figure 2-3. E-Delivery website for obtaining Oracle Goldengate software

At this point, we recommend that you review the readme file and release notes to best prepare for

the installation process. By investing a couple of hours, you will avoid most errors during the installation

and configuration phase .

Since we will use Oracle 11g with Goldengate, we will choose the Oracle GoldenGate 11.1.1.0.0 for

Oracle 11g on Windows XP software to download.

■ Note If you plan to use Oracle GoldenGate with Linux, you will also need to download the Oracle GoldenGate

software for the Linux platform.

Figure 2-4 provides the readme instructions for the Oracle GoldenGate media pack.

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Figure 2-4. README instructions for Oracle Goldengate software installation

Downloading from OTN

For readers who want to set up a test demo environment to learn how to work with Oracle Goldengate

software, we recommend that you download the software from OTN as shown below at

http://otn.oracle.com. Oracle allows you to use the GoldenGate software for educational purposes

without a purchased license. For use within a production environment, you would download the

software from the E-Delivery site. Figure 2-5 shows the Oracle Technology Network (OTN) website.

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Figure 2-5. OTN website

Since OTN is a massive site, it can be a little tricky to find where you actually obtain the Oracle

Goldengate software. Never fear—when you scroll down the page you will find the list of documentation

and software on the left side. Figure 2-6 shows the links to software downloads and documentation

available for Oracle GoldenGate.

Figure 2-6. Download Oracle Goldengate from OTN website

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Once you click the Downloads link from OTN, you will be shown the list of Oracle software for

download shown in Figure 2-7.

Figure 2-7. Download Oracle Goldengate from OTN website

On the Software Downloads heading on the OTN website, you will need to accept the license

agreement before downloading. Once you do so, you can download the Goldengate software for your

platform to use on a trial educational and non-production basis. Be sure to navigate to the heading for

Middleware software as shown in Figure 2-8 since Oracle classifies Goldengate as part of the Oracle

Fusion Middleware product family.

Figure 2-8. Download Oracle Goldengate from OTN website

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Click the GoldenGate hyperlink and you can download all of the required software packages for

Oracle Goldengate including Director and Veridata (Figure 2-9).

Figure 2-9. Download Oracle Goldengate from OTN website

Now that you understand how to obtain and download the Oracle Goldengate software and

documentation, it’s time for us to perform the installation and configuration for our test environments.

Understanding Your Environment

Before installing, you should have a good grasp of your target environment. For example, you may want

to install both Linux and Windows for the Oracle 11g database environments. In Table 2-1, we show a

test configuration that can be used for working with Oracle GoldenGate as a sandbox environment. We

also recommend that you install the sample schemas included with Oracle 11g to have sample test data

while working with GoldenGate. Our test platform will include the configuration in Table 2-1.

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