Re: [HACKERS] Tablespaces

Greg Stark wrote:
>
> > > I am expecting to hear some bleating about this from people whose
> > > preferred platforms don't support symlinks ;-). However, if we don't
>
> Well, one option would be to have the low level filesystem storage (md.c?)
> routines implement a kind of symlink themselves. Just a file with a special
> magic number followed by a path.
>
> I'm normally against reimplementing OS services but symlinks are really a very
> simple concept and simple to implement. Especially if you can make a few
> simplifying assumptions: they only ever need to appear as the final path
> element not as parent directories and tablespaces don't need symlinks pointing
> to symlinks. Ideally postgres also doesn't need to implement relative links
> either.

I just checked from the MinGW console and I see:

# touch a
# ln -s a b
# echo test >a
# cat b
# l ?
-rw-r--r-- 1 Bruce Mo Administ 5 Mar 2 23:30 a
-rw-r--r-- 1 Bruce Mo Administ 0 Mar 2 23:30 b
# cat a
test
# cat b
#

It accepts ln -s, but does nothing with it.

For tablespaces on OS's that don't support it, I think we will have to
store the path name in the file and read it via the backend. Somehow we
should cache those lookups.

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
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