156 Oracle Streams 11g Data Replication Handling Column Discrepancies In addition to the question regarding triggers, the other question that gets asked when configuring Oracle Streams replication is what happens if the source and destination tables are not identical. The column data types, number of columns, or column names might be different, or the table might not have a primary key or a unique key. The apply engine can handle such discrepancies between the source and destination tables. The following sections discuss how the apply engine handles various types of column discrepancies. Data Type Mismatch The apply process performs automatic data conversion for most captured data types when it detects that the data type of the column at the destination does not match the data type in the LCR from the source database. No additional configuration is required. Table 6-3 summarizes such data type conversions. Fewer Columns at Destination