Use the 'update' operation in Spark SQL to update the records directly, as it is the simplest method and requires minimal code.

Use the 'join' operation to merge the new data with the existing data and overwrite the table, which may improve performance for large datasets but requires careful handling of data types and null values.

Use the 'subtract' operation to remove the old records and then insert the new records, which is useful for removing old records but may not be suitable for adding new records efficiently.

Use a combination of 'join' and 'subtract' operations to update the records, providing a flexible and efficient approach that balances performance and data integrity.