Each database connections in SQLite can have only one journal mode.
See docs: SQLite Journal Modes
Deep Dives
The Journal Modes
Journal modes in SQLite are one of the mechanisms that SQLite uses to guarantee durability (the D in ACID).
| Journal Mode | Description | Durability | Concurrency |
|---|---|---|---|
| DELETE | (Default for Rollback Journal) The journal file is deleted after a transaction commits. | Good | Low |
| TRUNCATE | Similar to DELETE, but the journal file is truncated to zero length instead of being deleted. Generally faster than DELETE. | Good | Low |
| PERSIST | The journal file is not deleted or truncated after a transaction commits. Can improve performance if transactions are frequent, but increases the risk of data corruption if not managed carefully. Requires manual management (e.g., deleting the journal). | Fair | Low |
| MEMORY | The journal is kept in memory. Provides the fastest performance but offers no durability. If the system crashes, all changes are lost. | None | Low |
| WAL | Enables Write-Ahead Logging. Writes changes to a separate WAL file and periodically checkpoints them to the database file. | Excellent | High |
| OFF | Disables the journal entirely. Offers the fastest performance, but provides no durability or atomicity. Highly discouraged for most applications. | None | Low |