[sqlite] What is a virtual table's xSync() callback supposedtodo?

[Johnny Wezel]

On 26.10.2015 12:32, Richard Hipp wrote:
> On 10/26/15, Johnny Wezel <spam1 at wezel.name> wrote:
>> Should it check for external changes on the resource to check for
>> concurrency conflicts? The documentation isn't very specific on this.
>>
> It should push all cached changes into persistent storage.
>
That raises the question what xCommit() should do and how xRollback()
would be able to undo xSync().