Re: Big 7.1 open items

> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> >> Well, that opens up a completely different issue, which is what about
> >> moving tables from one tablespace to another?
> 
> > Are you suggesting that doing dbname/locname is somehow harder to do
> > that?  If you are, I don't understand why.
> 
> It doesn't make it harder, but it still seems pointless to have the
> extra directory level.  Bear in mind that if we go with all-OID
> filenames then you're not going to be looking at "loc1" and "loc2"
> anyway, but at "5938171" and "8583727".  It's not much of a convenience
> to the admin to see that, so we might as well save a level of directory
> lookup.

Just seems easier to have stuff segregates into separate per-db
directories for clarity.  Also, as directories get bigger, finding a
specific file in there becomes harder.  Putting 10 databases all in the
same directory seems bad in this regard.

> 
> > The general issue of moving tables between tablespaces can be done from
> > in the database.  I don't think it is reasonable to shut down the db to
> > do that.  However, I can see moving tablespaces to different symlinked
> > locations may require a shutdown.
> 
> Only if you insist on doing it outside the database using filesystem
> tools.  Another way is to create a new tablespace in the desired new
> location, then move the tables one-by-one to that new tablespace.
> 
> I suppose either one might be preferable depending on your access
> patterns --- locking your most critical tables while they're being moved
> might be as bad as a total shutdown.

Seems we are better having the directory be a symlink so we don't have
symlink overhead for every file open.  Also, symlinks when removed just
remove symlink and not the file.  I don't think we want to be using
symlinks for tables if we can avoid it.

--  Bruce Momjian                        |  http://www.op.net/~candle pgman@candle.pha.pa.us               |  (610)
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