Vacuum (Tools Menu)

When an object (table, index, or trigger) is dropped from the database, it leaves behind empty space. This empty space will be reused the next time new information is added to the database. In the meantime, the database file might be larger than strictly necessary. Also, frequent inserts, updates, and deletes can cause the information in the database to become fragmented - scrattered out all across the database file rather than clustered together in one place.

The Vacuum function cleans the database by copying its contents to a temporary database file and reloading the original database file from the copy. This eliminates free pages, aligns table data to be contiguous, and otherwise cleans up the database file structure.