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    The extra WAL sync following each transaction help ensure that 
    transactions are durable across a power loss.  Transactions are
    consistent with or without the extra syncs provided by
    synchronous=FULL.
    If durability is not a concern, then synchronous=NORMAL is normally
    all one needs in WAL mode.</p>

    <p>^The default setting is usually synchronous=FULL.
    The [SQLITE_EXTRA_DURABLE] compile-time option changes the
    default to synchronous=EXTRA.</p>

    <p>The TEMP schema always has synchronous=OFF since the content of
    of TEMP is ephemeral and is not expected to survive a power outage.
    Attempts to change the synchronous setting for TEMP are
    silently ignored.

    <p>See also the [fullfsync] and [checkpoint_fullfsync] pragmas.</p>
}