Oracle Goldengate 11g Complete Cookbook: Dig deep into administering Oracle Goldengate 11g using this comprehensive cookbook. From the very basics of installation to advanced features like migration, you'll learn the practical way through code scripts and examples.

There are various steps in configuring a GoldenGate environment. Some of the steps of this setup can be different for different database environments and requirements. In this chapter, we will go through the steps that should be performed for a simple replication and a complex one. We will also look into how to divide the load into multiple process groups for a busy system. Further, we will cover the set up required for ASM and RAC environments, and also how to encrypt the password and trail files. We will also look into the steps required for replication between tables with different structures.

In this recipe we will look at how to configure GoldenGate for continuous replication between two single node databases.

If your source system is a very busy OLTP system, with a high rate of data changes, then you will find that a single set of GoldenGate processes is not sufficient to replicate the load to the target environment in real time. In such a situation Oracle recommends splitting the load into multiple process groups.

How to do it...

In this recipe we will set up the following configuration for replicating the Order Entry schema:

As you can see from the preceding diagram, the replication setup performed here will consist of two Extract processes, two Datapumps, and four Replicat processes.

Perform the following steps in the source database:

1. Create...

If your source database is on ASM and the archive logs reside in an ASM diskgroup, the GoldenGate extract requires some additional configuration to be able to read them. In this recipe we will look at the additional parameters that you need to specify in the extract parameter file for this.

High Availability is the buzz word in today's world. The systems need to be available all the time. The applications store their data in the databases, so it becomes quite critical for the databases to be fault tolerant and always available. Oracle RAC is a popular choice when companies want to build resilience in their systems. More and more applications are becoming RAC aware and it is quite common to see companies migrating most of their applications to Oracle RAC-based database environments.

Replicating the data between Oracle RAC databases requires some additional setup. In this recipe we will look into what configuration steps are required to setup replication between Oracle RAC environments. We will not cover the set up required to make the GoldenGate replication highly available itself as there are many ways to do it and will be covered in separate recipes in Chapter 5, Oracle GoldenGate High Availability.

You would most likely create an Extract process with a dedicated Datapump process in the source environment. The Datapump process can suffer an outage in case of any network issue. However, it, resumes the trail file transfer to the remote site when it is up again. In such a situation you would want the Extract process to continue extracting the data into the trail files on the source system.

The trail files are stored in the filesystem which would be finite in space. The size of the trail file area will determine how many trail files can be stored, which in effect will determine how long the Extract process can continue generating the trail files while the Datapump process is down. This will determine the overall network outage capacity of your replication infrastructure. Clearly, it is quite important to size the trail file areas appropriately to avoid the situations where the Extract process has to be stopped because of lack of available space on...

This recipe will show you how to verify data transfer on a target system.

GoldenGate uses encryption keys for encrypting the passwords and trail files. You can use default keys or define custom encryption keys. Oracle recommends using custom encryption keys for encrypting passwords and trail files. In this recipe you will learn how to generate encryption keys using the keygen tool.

GoldenGate requires an Oracle user password to connect to the source and target databases. In this recipe you will learn how to encrypt the database passwords using the ENCRYPT utility.

The trail files are the key component in the GoldenGate configuration. Since these files hold the data that is extracted by the Extract process, keeping them in the default format poses a security risk. We can overcome this security risk by encrypting the trail files using various algorithms. In this recipe we will learn how to configure the automatic encryption of the trail files.

By default, GoldenGate expects the table definitions in your source and target environments to be similar. However, this may not always be the case. If you have defined the mapping between different tables in the source and target environments or the mapped tables have dissimilar structures, you would need to do some extra configuration to make GoldenGate replication work. In this recipe we will look into the additional steps that are required for this.