DOKK / manpages / debian 10 / xapian-tools / copydatabase.1.en
COPYDATABASE(1) User Commands COPYDATABASE(1)

copydatabase - Perform a document-by-document copy of one or more Xapian databases

copydatabase SOURCE_DATABASE... DESTINATION_DATABASE

copydatabase - Perform a document-by-document copy of one or more Xapian databases

Preserve the numbering of document ids (useful if you have external references to them, or have set them to match unique ids from an external source). If multiple source databases are specified and the same docid occurs in more one, the last occurrence will be the one which ends up in the destination database.
display this help and exit
output version information and exit
March 2019 xapian-core 1.4.11