4 Configuring Oracle GoldenGate

This chapter describes how to configure Oracle GoldenGate Replicat. This chapter contains the following sections:

Section 4.1, "Configuring Oracle GoldenGate Replicat"
Section 4.2, "Additional Oracle GoldenGate Configuration Guidelines"

4.1 Configuring Oracle GoldenGate Replicat

This section highlights the basic Replicat parameters that are required for most target database types. Additional parameters may be required. See the Oracle GoldenGate installation and configuration documentation for your target database and the Reference for Oracle GoldenGate for Windows and UNIX.

Perform these steps on the target replication server or target database system.

Configure the Manager process according to the instructions in Administering Oracle GoldenGate for Windows and UNIX.
In the Manager parameter file, use the PURGEOLDEXTRACTS parameter to control the purging of files from the local trail.
Create a Replicat checkpoint table. There are multiple options for this purpose. For instructions, see Administering Oracle GoldenGate for Windows and UNIX.
Create a Replicat group. For documentation purposes, this group is called rep.
```
ADD REPLICAT rep, EXTTRAIL remote_trail
```
Use the EXTTRAIL argument to link the Replicat group to the remote trail that you specified for the data pump on the source server.
Use the EDIT PARAMS command to create a parameter file for the Replicat group. Include the parameters shown in Example 4-1 plus any others that apply to your database environment.

Example 4-1 Parameters for the Replicat Group

-- Identify the Replicat group:
REPLICAT rep
-- State whether or not source and target definitions are identical:
SOURCEDEFS {full_pathname | ASSUMETARGETDEFS}
-- Specify database login information as needed for the database:
[TARGETDB dsn2,] [USERID user id[, PASSWORD pw]]
-- Specify error handling rules (See the NOTE following parameter file):
REPERROR (error, response)
-- Specify tables for delivery:
MAP owner.table, TARGET owner.table[, DEF template name];

Note:

In a recovery situation, it is possible that Replicat could attempt to apply some updates twice. If a multiset table is affected, this could result in duplicate rows being created. Use the REPERROR parameter in the Replicat parameter file so that Replicat ignores duplicate rows.

4.2 Additional Oracle GoldenGate Configuration Guidelines

The following are additional considerations to make once you have installed and configured your Oracle GoldenGate environment.

4.2.1 Handling Massive Update and Delete Operations

Operations that update or delete a large number of rows will generate discrete updates and deletes for each row on the subscriber database. This could cause a lock manager overflow on the Teradata subscriber system, and thus terminate the Replicat process.

To avoid these errors, you can do either of the following:

Temporarily suspend replication for these operations and then perform them manually on the source and target systems. To suspend replication, use the following command, which suspends replication for that session only. The operations of other sessions on that table are replicated normally.
```
set session override replication on;
```
```
commit;
```

4.2.2 Preventing Multiple Connections

By default, the Replicat processes create a new connection for catalog queries. You can prevent this extra connection by using the DBOPTIONS parameter with the NOCATALOGCONNECT option.

4.2.3 Performing Initial Synchronization

Perform an initial synchronization of the source and target data before using Oracle GoldenGate to transmit transactional changes for the first time to configure an initial load, see Administering Oracle GoldenGate for Windows and UNIX.