[Xapian-discuss] Atomic DB rebuilds

[James Aylett]

On Mon, Oct 04, 2004 at 06:06:34PM +0100, Olly Betts wrote:

> > So you could rename the _file_ over the old one, which certainly is
> > atomic, and will work on all NFS implementations that include lockd
> > (at least, AFAIK).
> 
> I can't see a reason why a symlink rename should be any less reliable
> than a file rename - the operation is essentially identical: the atomic
> part just requires replacing the inode number in a directory entry.

What if your backing filestore isn't a Unix semantics file system?
Windows supplies full reliable locking, but I can't remember if its
equivalent to symlinks is solid for this sort of thing (the things
that are used low-level by the POSIX emulation layer - I'm not even
sure if they're normally accessible on NTFS anyway).

I've had many problems, incidentally, with ln -sf not actually
updating the symlink, as it should do. Which is one reason why I don't
trust 'em.

J

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  James Aylett                                                  xapian.org
  james at tartarus.org                               uncertaintydivision.org