dmbuilddatadict command-line utility

An XStream capture process can only be initialized with an Oracle system change number (the first_scn value) that is associated with an archive log that contains an Oracle data dictionary. To replicate data with the CDC Replication Engine for Oracle XStream, XStream capture processes must be initialized based on such initialization points.

CDC Replication has detection mechanisms to determine the XStream capture initialization point, and it also reviews end user preferences and invokes the XStream API to create an initialization point that it could later use. If you revert the destination database to an older recovery point, or if a subscription that formerly ran with shared scrape can no longer participate in shared scrape, then the Oracle XStream capture process might need to be re-initialized at one of the initialization points that have been created prior to the CDC Replication bookmark.

CDC Replication includes the dmbuilddatadict command-line that can be scripted and scheduled to run routinely to create and leave a trace of capture initialization points that might be needed in the future. If no capture initialization points are available or the initialization points are in log files that are no longer available, CDC Replication could not continue replicating data from where it left off.

Recovery steps include either refreshing all tables that are associated with a private scraper, or all tables of all subscriptions that participate in shared scrape. You can use the mark capture point of the same set of tables as an alternative to refreshing the tables, but this method would skip over a section of the data and could lead to data loss.