SQLite3::backup() copies the contents of one database
into another, overwriting the contents of the destination database.
It is useful either for creating backups of databases
or for copying in-memory databases to or from persistent files.
Tip
As of SQLite 3.27.0 (2019-02-07), it is also possible to use the statement
VACUUM INTO 'file.db'; to backup the database to a new file.
The database name is "main" for the main database,
"temp" for the temporary database,
or the name specified after the AS keyword
in an ATTACH statement for an attached database.
destinationDatabase
Analogous to sourceDatabase
but for the destination.