https://www.sqlite.org/isolation.html https://www.sqlite.org/isolation.html "In WAL mode, SQLite exhibits "snapshot isolation". When a read transaction starts

https://www.sqlite.org/isolation.html https://www.sqlite.org/isolation.html "In WAL mode, SQLite exhibits "snapshot isolation". When a read transaction starts, that reader continues to see an unchanging "snapshot" of the database file as it existed at the moment in time when the read transaction started. Any write transactions that commit while the read transaction is active are still invisible to the read transaction, ..."