DB2 for i (Native)

Prerequisites

Before you add and set up the DB2 for i source connector, you need to set up the DB2 for i database for change data capture (CDC), as explained in the following sections. Limitations: The following capabilities are not supported in Sync:

remote journals or failover functionality
large objects such as CLOB, XML, TEXT, BLOB

Set Up DB2 for i for CDC

Journaling records database changes in journal receivers, which the change data capture (CDC) process uses to capture and replicate those changes to other systems in real-time or near real-time synchronization. A journal is a database object that serves as a tracking mechanism, capturing metadata about changes made to specific database objects. Each journal is linked to one or more journal receivers, which physically store the detailed change records, including before-and-after images of the data as well as metadata and transaction details. Because CDC depends on journaling to supply detailed change records, creating a journal and journal receiver and setting user permissions are the first steps in enabling CDC for DB2 for i, as explained in the next sections.

Create the Journal Receiver and Journal and Enable Journaling on Tables

Run the following command-line (CL) commands to create the journal receiver, journal, and enable journaling on tables:

   -- 1. Create a journal receiver.
CRTJRNRCV <ReceiverLibrary>/<ReceiverName>

   -- 2. Create a journal.
CRTJRN <JournalLibrary>/<JournalName> <ReceiverLibrary>/<ReceiverName>

   -- 3. Enable journaling on a file (table) by using the STRJRNPF command. As a best practice, capture both before-and-after images of the records to support features like auditing and recovery.
STRJRNPF <FileLibrary>/<FileName> <JournalLibrary>/<JournalName> IMAGES(*BOTH)

   -- If you already started journaling and need to change the image settings, submit the CHGJRNOBJ command.
CHGJRNOBJ OBJ((<FileLibrary>/<FileName> *FILE)) ATR(*IMAGES) IMAGES(*BOTH)

   -- To stop journaling for a specific physical file (table), use the ENDJRNPF command.
ENDJRNPF FILE(<FileLibrary>/<FileName>) JRN(<JournalLibrary>/<JournalName>)

To verify that journaling is enabled for a table, or for details about the journals and their journal receivers, execute the following queries:

SELECT * FROM QSYS2.JOURNAL_RECEIVER_INFO WHERE JOURNAL_RECEIVER_LIBRARY = <ReceiverLibrary>;
SELECT * FROM QSYS2.JOURNAL_INFO WHERE JOURNAL_LIBRARY = '<JournalLibrary>';
SELECT * FROM QSYS2.JOURNALED_OBJECTS WHERE JOURNAL_LIBRARY = '<JournalLibrary>';

The following example creates the RCV01 journal receiver and the JRN1 journal. Then, it adds the PRODUCTS table for journaling by using QSYS2.QCMDEXC to call any CL command through the JDBC tool. All of the objects are created in the TEST2 schema/library.

   -- 1. Create a NEW journal receiver.
CALL QSYS2.QCMDEXC('CRTJRNRCV TEST2/RCV01');

   -- 2. Create a journal.
CALL QSYS2.QCMDEXC('CRTJRN TEST2/JRN1 TEST2/RCV01');

   -- 3. Start journaling tables/files.
CALL QSYS2.QCMDEXC('STRJRNPF FILE(TEST2/PRODUCTS) JRN(TEST2/JRN1) IMAGES(*BOTH)');

   -- 4. Stop journaling tables/files.
CALL QSYS2.QCMDEXC('ENDJRNPF FILE(TEST2/PRODUCTS) JRN(TEST2/JRN1)');

VALUES CURRENT_SCHEMA; -- TEST2
SELECT * FROM QSYS2.JOURNAL_RECEIVER_INFO WHERE JOURNAL_RECEIVER_LIBRARY = CURRENT_SCHEMA;
SELECT * FROM QSYS2.JOURNAL_INFO WHERE JOURNAL_LIBRARY = CURRENT_SCHEMA;
SELECT * FROM QSYS2.JOURNALED_OBJECTS WHERE JOURNAL_LIBRARY = CURRENT_SCHEMA;

When you create a CDC job in Sync, you select the journal and schema to determine which tables are available for capture.

Set Required User Permissions

To verify all permissions for the user to which you are connected, submit the following query:

SELECT * FROM QSYS2.OBJECT_PRIVILEGES WHERE AUTHORIZATION_NAME = '<CDCUser>'

If the user lacks privileges to the journal, journal receiver, or the schema (library) from which you want to capture changes, run the following CL commands:

GRTOBJAUT OBJ(<JournalLibrary>) OBJTYPE(*LIB) USER(<CDCUser>) AUT(*EXECUTE)
GRTOBJAUT OBJ(<JournalLibrary>/*ALL) OBJTYPE(*JRNRCV) USER(<CDCUser>) AUT(*USE)
GRTOBJAUT OBJ(<JournalLibrary>/<JournalName>) OBJTYPE(*JRN) USER(<CDCUser>) AUT(*USE *OBJEXIST)

GRTOBJAUT OBJ(<ReceiverLibrary>) OBJTYPE(*LIB) USER(<CDCUser>) AUT(*EXECUTE)
GRTOBJAUT OBJ(<ReceiverLibrary>/*ALL) OBJTYPE(*FILE) USER(<CDCUser>) AUT(*USE)

To execute the commands through a Java Database Connectivity (JDBC) tool, use this command:

CALL QSYS2.QCMDEXC(‘CL COMMAND’);

Add the DB2 for i Connector

Authenticate to DB2 for i

After you add the connector, you need to set the required properties.

Server: Enter the address or host name of the DB2 for i server. The default server is localhost.
Database: Enter the name of your DB2 for i database.
Port: Enter the port number for your server. The default port is 446.
User: Enter the username that you use to authenticate to the DB2 for i database.
Password: Enter the password that you use to authenticate to the DB2 for i database.

Complete Your Connection

To complete your connection:

Define advanced connection settings on the Advanced tab. (In most cases, though, you should not need these settings.)
Click Create & Test to create your connection.

Create a Change Data Capture (CDC) Job with Journal and Schema Selections

This section explains how to create a change data capture (CDC) job for DB2 for i and how to configure row identification for tables without primary keys.

Create the CDC Job

Follow these steps to create a CDC job for DB2 for i:

Enter a name for your job.
Select your DB2 for i source.
Select your destination.
Specify values for the following fields:
- Journal Library
- Journal Name
- Source Schema
You can select the values for each of these properties from their drop-down lists. Sync validates these values against the DB2 for i system to ensure that the journal exists and is properly configured.
Click Add Job. After the job is created, the journal settings are displayed in the CDC engine settings and cannot be modified.
Continue to the job’s Task tab for table selection. Only tables that meet the following criteria are displayed:
- The table is journaled.
- The table is associated with the selected journal.
- The table belongs to the selected schema.

If you change the journal or schema, previously selected incompatible tables are automatically deselected.

When you create DB2 for i CDC jobs through the API, you must provide the journal library and journal name.

Configure Row Identification for Tables without Primary Keys

When you configure a change data capture (CDC) job for DB2 for i, you can use the relative record number (RRN) as the value for the _cdatasync_id column. This approach provides a stable identifier for tables that do not have a primary key. By default, Sync uses the RRN as the identifier for DB2 for i records (the default value is Db2Rrn). To override this and use an MD5-based row hash instead, set the following SyncIdSourceColumn job option in the Additional Options field on the job’s Advanced tab:

SyncIdSourceColumn=RowHash

When you use the RRN-based identifier:

The _cdatasync_id column is represented as a BigInt data type.
The identifier is derived directly from the physical row location in the source table.
The _cdatasync_id column can be used as a partition key for destinations that support partitioning.

Reorganizing the source table resets the RRN values for all rows. This change invalidates previously generated _cdatasync_id values because they no longer correspond to the same physical rows. To correct this issue, you must perform a full re-sync of the affected tables. For details, see Re-Syncing Job Task Execution.

Replicate Members of Multi-Member Physical Files

Sync replicates each member of a multi-member physical file as its own table. To choose a member, create an SQL alias that references that member.

If your CDC jobs include multi-member physical files, Sync now replicates only the default member instead of all members. Add an alias for each of the other members to avoid losing replication coverage.

Configure Replication

To configure replication for multi-member physical files:

Journal the physical file, as shown below. Journaling applies to all members, including those added later. Aliases do not require separate journaling.
STRJRNPF FILE(MYLIB/MYFILE) JRN(MYLIB/MYJRN) IMAGES(*BOTH)

Create an alias for each member you want to replicate:

CREATE ALIAS MYLIB.MYFILE_MBR1 FOR MYLIB.MYFILE (MBR1);

Add the aliases as tasks. The aliases appear in the table list next to their associated physical file.

Replication Behavior

Replication depends on whether you select an alias or the physical file:

Alias: Using an alias replicates only the member that is referenced by the alias, including the initial load and subsequent changes. The target table uses the alias name.
Physical file: Using a physical file replicates only the default member (the member with the same name as the physical file).
Members without selected aliases: These members are ignored.

Getting Started

Connections

Jobs

Events

Transformations

Release Notes

License

Prerequisites

Set Up DB2 for i for CDC

Create the Journal Receiver and Journal and Enable Journaling on Tables

Set Required User Permissions

Add the DB2 for i Connector

Authenticate to DB2 for i

Complete Your Connection

Create a Change Data Capture (CDC) Job with Journal and Schema Selections

Create the CDC Job

Configure Row Identification for Tables without Primary Keys

Replicate Members of Multi-Member Physical Files

Configure Replication

Replication Behavior

​Prerequisites

​Set Up DB2 for i for CDC

​Create the Journal Receiver and Journal and Enable Journaling on Tables

​Set Required User Permissions

​Add the DB2 for i Connector

​Authenticate to DB2 for i

​Complete Your Connection

​Create a Change Data Capture (CDC) Job with Journal and Schema Selections

​Create the CDC Job

​Configure Row Identification for Tables without Primary Keys

​Replicate Members of Multi-Member Physical Files

​Configure Replication

​Replication Behavior

Prerequisites

Set Up DB2 for i for CDC

Create the Journal Receiver and Journal and Enable Journaling on Tables

Set Required User Permissions

Add the DB2 for i Connector

Authenticate to DB2 for i

Complete Your Connection

Create a Change Data Capture (CDC) Job with Journal and Schema Selections

Create the CDC Job

Configure Row Identification for Tables without Primary Keys

Replicate Members of Multi-Member Physical Files

Configure Replication

Replication Behavior