Originally Posted by BetterRed
 - this can be confirmed by looking at Library->Library Maintenance->Library metadata backup status
The backup files are written in a separate background thread at about 1 book/sec (on my rig at least). So if I delete a tag that is used on a 1,000 books it will take about 15 minutes to write the 1,000 fresh metadata.opf files. It's done this way so that the user can continue to do their work.
And if you close calibre down before it finishes writing the backups it'll continue writing them next time calibre is run against the same library. The calibredb backup_metadata command is available to do any pending metadata.db writes (without the delay), I run it against all my libraries when I quit calibre . FWIW : I have a custom column (Last Change Date) that I maintain manually using F2->'='->Enter on the Book list cell. The '=' sets a date to current datetime (Now)
@ chaley - Would be be nice if Shift+F2 set a date to 'now', and if Ctrl+F2 cleared a date/number  . BR |