You can reorder the synchronization process so that indexes are created first.
In the Settings tab, click the Sync Behavior sub-tab.
Click Create indexes before table population.
This can have either a negative or positive effect on performance and space requirements of a full synchronization, depending upon the database system.
If the target is an Oracle database, it will be faster to create the indexes after the load of the data. Inserting rows with an existing index updates the indexes on every insert, whereas creation of an index at the end of the synchronization is somewhat more efficient.