There are several types of supplemental logging
Minimal supplemental logging ensures that products leveraging LogMiner technology will have sufficient information to support chained rows and cluster tables.
Primary key supplemental logging includes the primary key for rows affected by UPDATE and DELETE changes.
Unique key supplemental logging includes all columns for a unique key are written to undo if any unique key columns are modified.
Foreign key supplemental logging includes all other columns belonging to a foreign key will be logged in the undo if any foreign key columns are modified.
If no primary key or unique key is available then it is possible to specify that all columns are logged. In this case all columns in a row will be logged in the undo. When the row is replicated in the target database, equality predicates will be applied to all columns. LONG, LONG RAW and LOB columns will be omitted from the supplemental logging.
Procedural replication supplemental logging includes additional information in the redo log during invocation of procedures in Oracle-supplied packages for which procedural replication is supported. I have never investigated this option.
Oracle implements supplemental logging at database level, schema level and at table level. The three implementations are significantly different:
Database level supplemental logging is configured in the control file. The parameter does not appear to be stored in the database itself.