Q Replication - Creating Q subscriptions for unidirectional replication

Creating target object profiles
You can create profiles in the Replication Center or ASNCLP command-line program to specify your own default naming convention for objects that the administration tools create at the target server.

Creating Q subscriptions for unidirectional replication
By creating Q subscriptions for unidirectional replication, you define how data from source tables is replicated to target tables or is passed to parameters in a stored procedure for data manipulation.

Data distribution configurations (Q Replication to SQL Replication)
In a data distribution or fan-out configuration that uses Q Replication and SQL Replication, transactions are replicated from a source table to a target table in Q Replication, and the target table then acts as the source table for one or more SQL Replication Apply programs.

Source columns for Q subscriptions (unidirectional replication)
By default when you create Q subscriptions, changes to all columns that are in the source table are replicated to the target table or stored procedure. However, when you create a Q subscription for unidirectional replication, you can replicate a subset of the columns that are in the source table instead of all of the columns.

How often the Q Capture program sends a message (unidirectional replication)
When you create Q subscriptions, you can specify when the Q Capture program sends messages to the Q Apply program. The Q Capture program can send a message either only when the columns change that are part of the Q subscription or every time that a column in the source table changes.

How source columns map to target columns (unidirectional replication)
For existing target tables, you can specify how you want the data from source columns to map to target columns. If a target table does not exist, the Replication Center or ASNCLP program create the target table (or nickname if you have non-DB2 target tables) with the same columns as the source table.

Before-image columns in Q Replication
When you create a Q subscription, by default only the changed (after-image) value in a column is replicated. You can also choose to replicate the previous (before-image) value of selected columns in a source table.

Index or key columns for targets (unidirectional replication)
The Q Apply program uses a primary key, unique constraint, or unique index at the target to enforce the uniqueness of each row when it applies the row to target tables or parameters in stored procedures.

Options for unexpected conditions in the target table (unidirectional replication)
The Q Apply program updates the targets with changes that occur at the source table. If other applications are also making changes to the target, then the Q Apply program might encounter rows in the target that are different than expected.

Options for conflict detection (unidirectional replication)
The choices that you make for conflict rules and conflict actions affect the behavior of how rows are applied. The conflict rules determine how much of the data is checked to detect a conflict and the types of conflicts that are detected. When you choose to have more data checked for conflicts, then the Q Capture program must send more data to the Q Apply program to make that data available to be checked, which might influence performance and network traffic.

Error options for Q Replication
In Q Replication, you can specify what action the Q Apply program takes when it encounters errors, such as SQL errors, in your environment. The option that you choose depends on the level of granularity at which you want to isolate and fix the problem. The same error options apply for both unidirectional and multidirectional replication.