Which operation should you schedule to remove Delta Lake data files that are no longer used?

Which operation should you schedule to remove Delta Lake data files that are no longer used?

• A. VACUUM
• B. OPTIMIZE
• C. ANALYZE
• D. REORG

Answer: (A)

Delta Lake keeps data as Parquet files and uses a transaction log to track which files are part of the current table state. Over time, deletes and updates leave older, unreferenced files on storage. Scheduling VACUUM removes those obsolete files, reclaiming space and keeping the data footprint smaller. It deletes files based on the transaction log and a configured retention period (default is typically around seven days). This is the tool designed for cleaning up unused data files. Other operations don’t perform this cleanup: OPTIMIZE reorders and compacts data for faster queries, ANALYZE gathers statistics for planning, and REORG isn’t the Delta Lake mechanism for removing obsolete files.

Delta Lake keeps data as Parquet files and uses a transaction log to track which files are part of the current table state. Over time, deletes and updates leave older, unreferenced files on storage. Scheduling VACUUM removes those obsolete files, reclaiming space and keeping the data footprint smaller. It deletes files based on the transaction log and a configured retention period (default is typically around seven days). This is the tool designed for cleaning up unused data files.

Other operations don’t perform this cleanup: OPTIMIZE reorders and compacts data for faster queries, ANALYZE gathers statistics for planning, and REORG isn’t the Delta Lake mechanism for removing obsolete files.