When the Q Capture program publishes a message for publications
When you create publications, you can specify that the Q Capture program publishes a message either every time that a column in the source table changes, or only when columns that are part of a publication change.
The following sections describe the two different types of events that can cause the Q Capture program to publish a message:
- Message is sent only when columns in publications change
- Message is sent every time a change occurs in the source table
Message is sent only when columns in publications change
By default, the Q Capture program publishes a message only when the change occurs in columns that you selected for the publications.
Example: Assume that you have 100 columns in your source table and you select 25 of those columns to be published in a publication. If you specify for a message to be sent only when columns in publications change, then any time a change is made to any of the 25 columns that are part of the publication, the Q Capture program publishes an message. Any time a change is made in any of the 75 columns that are not part of the publication, the Q Capture program does not publish an message.
Message is sent every time a change occurs in the source table
You can define publications so that the Q Capture program publishes a message every time a change occurs in the source table. If you are publishing only a subset of the columns in the source table, then the Q Capture program publishes a message even if the change occurs in a column that is not part of a publication.
Example: Assume that you have 100 columns in your source table and you select 25 of those columns to be published in a publication. If you specify for a message to be sent every time a change occurs in the source table, any time that a change is made to any of the of the 100 columns in your source table, the Q Capture program publishes an message.