On 1 Feb 2016, at 9:23am, bm.email01 at gmail.com wrote: > --- > No, SQLite does not. On COMMIT it fsyncs the database file and unlinks the > journal[1], but does not fsync the directory. > --- > > Since that can cause the last transaction to be lost, despite Sqlite > returning a 'Commit successful' code to the application, doesn't that mean > that Sqlite is _not_ truly 'Durable' (per ACID)?
1) The fault here is the file system not SQLite. This one particular file system has this strange requirement that you fsync the directory. SQLite is ACID. It's the file system that messes it up. SQLite cannot defend against untrustworthy middleware -- sooner or later a programmer has to trust their hardware is doing what it says it's doing. 2) Even if this were fixed, with an fsync of the directory included in the VFS, your storage system lies to the OS. So you still wouldn't get ACID behaviour because your storage system isn't ACID. SQLite cannot defend against untrustworthy storage -- sooner or later a programmer has to trust their hardware is doing what it says it's doing. 3) For both the above problems SQLite still neither loses data nor corrupts the database file. If the program crashes the file is automatically closed. When the SQLite API is used to reopen the file the unexpected close will be discovered and corrected for. Simon.
