Detailed Explanation

To minimize daily data transfer between Azure Blob Storage and Azure Data Lake Storage Gen2, the solution must focus on incremental loading - transferring only new or modified files each day rather than all files.

✅ Correct Answers: A and C

A: Specify a file naming pattern for the destination

• This enables proper organization of files in the {Year}/{Month}/{Day}/ folder structure
• Ensures files are stored systematically, making it easier to track which files have already been copied
• Supports incremental loading by maintaining clear file organization and preventing duplicate transfers

C: Filter by the last modified date of the source files

• This is the primary mechanism for minimizing data transfer
• Allows the pipeline to copy only files modified on the current day
• Prevents re-transferring files that haven't changed since the last load
• Directly addresses the core requirement of reducing daily data volume

❌ Incorrect Answers

B: Delete the files in the destination before loading the data

• This would increase data transfer by forcing re-upload of all files daily
• Contradicts the goal of minimizing transfer volume
• Creates unnecessary overhead and potential data loss risk

D: Delete the source files after they are copied

• While this prevents duplicate transfers, it's not necessary for minimizing data transfer
• Could disrupt source system operations and create data retention issues
• Filtering by modification date achieves the same goal without destructive operations

Optimal Strategy

The combination of file naming patterns (A) and date filtering (C) creates an efficient incremental loading solution:

• Date filtering ensures only new/modified files are transferred
• Proper file organization supports tracking and prevents duplication
• This approach minimizes network bandwidth usage and reduces processing time while maintaining data integrity.