29 Configuring Oracle GoldenGate

Learn about the prerequisites and tasks for configuring Oracle GoldenGate Replicat for Oracle TimesTen database.

Topics:

• Creating a Checkpoint Table
  
• Configuring Oracle GoldenGate Replicat
  
• Additional Oracle GoldenGate Configuration Guidelines
  

Creating a Checkpoint Table

Replicat maintains its checkpoints in a checkpoint table in the Teradata target database (the database where you use DBLOGIN). Each checkpoint is written to the checkpoint table within the Replicat transaction. Because a checkpoint either succeeds or fails with the transaction, Replicat ensures that a transaction is only applied once, even if there is a failure of the process or the database.

Use the following GGSCI command on the target system, to create the Replicat checkpoint table.

ggsci> ADD CHECKPOINTTABLE schema.chkptabl Successfully created checkpoint table schema.chkptabl

For more information about creating a checkpoint table, see Administering Oracle GoldenGate.

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.

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

1. Configure the Manager process according to the instructions in Administering Oracle GoldenGate.
2. In the Manager parameter file, use the PURGEOLDEXTRACTS parameter to control the purging of files from the local trail.
3. Create a Replicat checkpoint table. There are multiple options for this purpose, see Administering Oracle GoldenGate.
4. Create a Replicat group. For documentation purposes, this group is called rep.

   ADD REPLICAT rep, EXTTRAIL remote_trail, CHECKPOINTTABLE owner.table
   

   Use the EXTTRAIL argument to link the Replicat group to the remote trail that you specified for the data pump on the source server.

5. Use the EDIT PARAMS command to create a parameter file for the Replicat group. Include the parameters shown in Example 29-1 plus any others that apply to your database environment.

Example 29-1 Parameters for the Replicat Group

-- Identify the Replicat group:
REPLICAT rep
-- Specify database login information as needed for the database:
[TARGETDB target_dsn_name,] [USERID user id[, PASSWORD pw]]
-- Specify tables for delivery:
MAP owner.source_table, TARGET owner.target_table;

Additional Oracle GoldenGate Configuration Guidelines

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

• Handling Massive Update and Delete Operations
  
• Preventing Multiple Connections
  
• Performing Initial Synchronization
  

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, 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;

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.

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.