From Newsgroup: comp.lang.python

Mr Serdar Yegulalp occasionlly comes up with useful titbits of
information, but I’m not sure I’d count this among them <https://www.infoworld.com/video/4164431/how-to-back-up-sqlite-databases-the-right-way-not-by-copying-them.html>.

Does anybody else use SQLite’s backup API? I’ve never bothered,
because SQLite is a single-user DBMS. To backup a database, I just
shut down the program accessing it, and do a regular file copy on the
database file. Simple.

I think the backup API might be useful from within the app accessing
the database itself, to provide its own backup function while it is
still running. Again, not something I’ve felt much need for; in my experience, long-running service-style apps tend to use multiuser
DBMSes, which can handle multiple simultaneous connections without
things getting confused. And backing them up is easily done by making
yet another connection from a database dump utility, usually provided
as part of the DBMS package.
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From Newsgroup: comp.lang.python

On 2026-05-10, Lawrence D’Oliveiro <ldo@nz.invalid> wrote:

Mr Serdar Yegulalp occasionlly comes up with useful titbits of
information, but I’m not sure I’d count this among them
<https://www.infoworld.com/video/4164431/how-to-back-up-sqlite-databases-the-right-way-not-by-copying-them.html>.

Does anybody else use SQLite’s backup API? I’ve never bothered,
because SQLite is a single-user DBMS. To backup a database, I just
shut down the program accessing it, and do a regular file copy on the database file. Simple.

You don't even need to do that - just lock the database during the copy.
For most SQLite instances where the data is small the duration of the
lock would probably be barely noticeable.

I think the backup API might be useful from within the app accessing
the database itself, to provide its own backup function while it is
still running. Again, not something I’ve felt much need for; in my experience, long-running service-style apps tend to use multiuser
DBMSes, which can handle multiple simultaneous connections without
things getting confused. And backing them up is easily done by making
yet another connection from a database dump utility, usually provided
as part of the DBMS package.

They explain why the backup API exists here:

https://sqlite.org/backup.html

* Any database clients wishing to write to the database file while a
backup is being created must wait until the shared lock is
relinquished.
* It cannot be used to copy data to or from in-memory databases.
* If a power failure or operating system failure occurs while copying
the database file the backup database may be corrupted following
system recovery.

I must admit I don't understand the last one - a power failure during
the backup would be incredibly rare, and if it happens, just re-do the
backup again. (Obviously you wouldn't overwrite the previous backup
with the new backup, in case the primary database died during the
backup.)
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