Why does removing files from a stage improve the next COPY INTO operation?

• A. Because it will have fewer files to copy
• B. Because it will scan fewer files
• C. Because it will compress files more easily
• D. None

Answer: (B)

COPY INTO starts by listing and evaluating the files in the stage to decide which ones to load. Each file adds work during this discovery and metadata scanning step. By removing files, you reduce the total number of candidate files the system must examine, so the file discovery happens faster and the load proceeds more quickly. This improvement comes from fewer files to scan, not from changes in compression or how the data is read. If you want to further optimize, using a pattern to limit which files are considered can help as well.