1 - Tune INSERTS - Parallelized programs doing concurrent INSERT statements
2 - Tune SQL*Loader - Using sqlldr Direct Load, and adjusting parameters improves INSERT performance.
3 - Tune imports - Use Oracle Data Pump (Formally Oracle import utility) - Here are tips for hypercharging Oracle import.
Optimizing Oracle INSERT performance
When using standard SQL statements to load Oracle data tables, there are several tuning approaches:
a - Manage segment header contention for parallel inserts - Make sure to define multiple freelist (or freelist groups) to remove contention for the table header. Multiple freelists add additional segment header blocks, removing the bottleneck. You can also use Automatic Segment Space Management (bitmap freelists) to support parallel DML, but ASSM has some limitations.
Read more about secrets for optimizing Oracle table inserts here:
http://oracle-tips.c.topica.com/maalfseabGRCBcilq9pb/