Re: Making metadata storage SQL-driven

[Jamie McCracken <jamiemcc blueyonder co uk>]

Rodrigo Moya wrote:
> On Thu, 2005-09-01 at 07:31 -0400, Luis Villa wrote:
>
> > On 9/1/05, Jamie McCracken <jamiemcc blueyonder co uk> wrote:
> >
> > > Rodrigo Moya wrote:
> > >
> > > > On Thu, 2005-09-01 at 12:10 +0100, Jamie McCracken wrote:
> > > >
> > > >
> > > > > Christian Neumair wrote:
> > > > >
> > > > >
> > > > > > I really wonder why we rely on files for our metadata. It has issues [1]
> > > > > > where a synchronous fopen and read or write operation would really take
> > > > > > too long, requiring us to schedule reads/writes. Without doing any
> > > > > > performance measures, I think this could significantly speed up our
> > > > > > metadata code for big directories. I think we should do the same as
> > > > > > beagle, and rely on a tiny SQL server, doing all our metadata operations
> > > > > > synchronously. I'm not a big fan of EAs, since they seem to be some
> > > > > > different flavors and inconsistencies among various implementations.
> > > > > >
> > > > > > [1] http://makeashorterlink.com/?Y364247BB
> > > > >
> > > > > you are correct and thats why Im building such a system for Gconf/common
> > > > > config system, general metadata server, schematic storage (like winFS),
> > > > > indexing and anything else that needs fast structured storage.
> > > > >
> > > > > My system is called DDS (data desktop server) and is simply a dbus
> > > > > wrapper around the embedded mysql DB.
> > > >
> > > >
> > > > please don't use MySQL directly! First, you will impose users to install
> > > > and configure a DB server, which might not be possible in all cases.
> > >
> > > the *embedded* version of mysql is just a shared object - you dont need
> > > to install the full mysql to get it. RPMs for the *embedded* version are
> > > on mysql's website. The *embedded* mysql is the same as sqlite in that
> > > regard.
> >
> > I presume that ny metadata system really should be part of the
> > platform so that other apps can access it; that would rule out mysql
> > on licensing concerns.
>
> right, mysql is GPL, so can't really link to it from LGPL code.

Dbus IPC wrapper - not an issue!

> In gnome-db (and other projects) we asked for a special treatment so
> that we could link against their GPL libs from our LGPL ones, but with
> no answer so far AFAIK from them.
>
> So, again, for embedded dbs', use SQLite, and, if you use libgda, you
> allow admins to set up the database on a different server, like
> PostgreSQL, Oracle, MySQL, etc

I cant do that cause I need the full text indexing of mysql for my indexer!

http://dev.mysql.com/doc/mysql/en/fulltext-search.html

unfortuantely thats specific to mysql and not available on other RDBMS.

--
Mr Jamie McCracken
http://www.advogato.org/person/jamiemcc/