Allow Replication of a Subset of Columns from Db2 for z/OS using Db2 Data Gate

Allow customers to define which columns of a Db2 for z/OS table should be replicated to Db2 Data Gate, reducing storage requirements, replication overhead, and unnecessary data exposure.

Today, when a table is added to Db2 Data Gate using the SYSPROC.ACCEL_ADD_TABLES process, the accelerator-shadow table is created using all supported columns from the source Db2 for z/OS table. The product automatically excludes only unsupported columns, such as specific data types or columns with unsupported attributes.

However, many real-world use cases require only a subset of the columns available in the source table. Organizations often replicate large operational tables containing hundreds of columns while applications require only a small portion of the available data.

Currently, there is no supported mechanism to intentionally select which columns should be replicated to Db2 Data Gate.

Benefits:

Adding support for column-level replication would provide several benefits:

• Reduced storage consumption on the target Db2u environment.
• Reduced network traffic during initial loads and ongoing replication.
• Lower CPU and resource utilization for replication processing.
• Faster initial table loading and synchronization times.
• Improved governance and security by avoiding replication of unnecessary data.
• Simplified compliance with data minimization requirements.
• Better support for applications that typically consume limited subsets of large operational tables.
• Reduced operational costs associated with maintaining replicated datasets.

This capability would be particularly valuable for very large enterprise tables containing hundreds of columns and billions of rows, where only a small subset of attributes is required in the target environment.

Suggested Implementation:

One possible implementation approach would be to extend the SYSPROC.ACCEL_ADD_TABLES XML specification to allow optional column selection during table registration:

<table name="TABLENAME" schema="CREATOR">
   <columns>
      <column name="COL1"/>
      <column name="COL2"/>
      <column name="COL5"/>
      <column name="COL6"/>
   </columns>
</table>

Only the specified columns would be included in the accelerator-shadow table and subsequent replication process.