Hi @minhhung0507,

The VACUUM command on a Delta table does not delete the _delta_log folder, as this folder contains all the metadata related to the Delta table. The _delta_log folder acts as a pointer where all changes are tracked. In the event that the _delta_log folder is accidentally deleted, it cannot be recovered unless bucket versioning enabled. If versioning is enabled, you can restore the deleted files and run the FSCK REPAIR command to fix the Delta table. However, it's important to understand how Delta performs the FSCK operation under the hood.

For more understanding on Vacuum, refer following link VACUUM | Databricks on Google Cloud

If you are still facing issue to query table cause of missing parquet files, you can fix it by running following command, refer following link FSCK REPAIR TABLE | Databricks on Google Cloud

FSCK REPAIR TABLE table_name [DRY RUN]

Regards,
Hari Prasad