Options for how the Capture program stores updates

By default updates to the source table are stored in a single row in the CD table. In some cases you should instruct the Capture program or triggers to capture updates as DELETE and INSERT pairs that are stored in two rows.

You must capture updates as DELETE and INSERT statements when your source applications update one or more columns referenced by a predicate on the subscription-set member.

Example: Suppose that you plan to define a target that subscribes only to source data with a predicate based on a specific column value (for example, WHERE DEPT = 'J35'). When you change that column (for example, to DEPT='FFK'), the captured change will not be selected for replication to the target because it does not meet the predicate criteria. That is, your new FFK department will not be replicated because your subscription-set member is based on Department J35. Converting the updates to a DELETE and INSERT pair ensures that the target-table row is deleted.

Each captured update is converted to two rows in the CD (or CCD) table for all columns. You might need to adjust the space allocation for the CD (or CCD) table to accommodate this increase in captured data.