SSIS Truncate / Delete all lines and Reinsert versus Insert / Update delta

I need to write an SSIS package to import data from approximately 1400 tables, each containing several million records from Oracle to SQL Server every 15 days. Which approach is recommended:

On every import the foreach table in SQL Server

• Trim / delete all records and import all records from Oracle
• Foreach row in every table in SQL Server, check if it is updated in the corresponding Oracle table, if yes, update it and insert new rows if any.

Thanks in advance.