--- Yves Goergen <[EMAIL PROTECTED]> wrote: > in a scenario when multiple operations need to be transactionally > synchronised, I have a file that must be deleted when the database > records are added successfully, but the database operations must be > rolled back, if the file cannot be deleted. > > I'm currently using a transaction for this on the database side and > rolling it back if the file cannot be deleted. But what if the file is > gone and then SQLite says it doesn't accept my records? Since we're > inside a transaction, integrity checks should be deferred until a > COMMIT. Is there a way to tell whether the COMMIT will succeed under the > current conditions so that I can safely delete the file? > > Would that work with nested transactions or are integrity checks also > deferred to the most outer transaction? I never used nested transactions > so I have no experience with it.
There's no nested transaction support at this time, although it's on the to do list: http://www.sqlite.org/cvstrac/wiki?p=ToDo But you will always have trouble with external synchronization with resources that do not support 2PC anyway. http://en.wikipedia.org/wiki/Two-phase_commit Are you able to store this file in the database itself as a BLOB? You might be able to use Libsqlfs, a POSIX style file system on top of an SQLite database. (I've never tried to use it). http://www.nongnu.org/libsqlfs/ Assuming this library works, your users can always be guaranteed the files are valid, and are erased in concert with your database transactions. ____________________________________________________________________________________ Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center. http://autos.yahoo.com/green_center/ ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
