The Connect CDC Director uses the table-mapping algorithm to search for a target table to which a given source table will be mapped.
For each available table you select from the source server, the Connect CDC Director searches the target server for an exact match of the fully qualified table name. Connect CDC Director looks for a table whose table, owner, and (if applicable) catalog names are identical to those of the sending table’s, including capitalization (case).
The target server Available Tables cache is searched first; if this is empty or if there is no match, the target table must be cached. This means that a search must be performed to populate the cache of Available Tables. For more information refer to Refresh the available tables cache.
If an exact match is found, Connect CDC Director adds the source table to the list of sending tables, adds the target table to the list of receiving tables, sets up a Default column mapping between the sending table and the matching receiving table, and moves on to the next sending table, if any.
If an exact match is not found, Connect CDC Director searches the target server cache (but not the catalog) for a “reasonable” match: a table whose fully-qualified name is the same except for case, or whose owner and table names are the same except for case (whether or not the catalog names match), or whose table names are the same except for case (whether or not the catalog and owner names match).
If only one reasonable match is found, Connect CDC Director adds the source table to the list of sending tables, adds the target table to the list of receiving tables, sets up a default column mapping between the sending table and the matching target table, and moves on to the next source table, if any.
If more than one reasonable match is found, the Connect CDC Director adds the source table to the list of sending tables without mapping it to a target table, and moves on to the next source table, if any.
If no reasonable match is found, the Connect CDC Director adds the source table to the list of sending tables without mapping it to a target table, and moves on to the next source table, if any.