Re: Proposing Tracker for inclusion into GNOME 2.18

[Joe Shaw <joeshaw novell com>]

Hi,

Jamie McCracken wrote:
> Joe Shaw wrote:
> > What I meant is that Tracker has to read and process all that
> > information.  One thing I've learned from Beagle is that there is a lot
> > of broken data out there, or that our code to process that data was
> > broken.  (This has particularly been a problem with non-free file
> > formats.)
>
> complete non-issue for tracker as all text and metadata is extracted out 
> of process ergo it cannot cause leaks or crashes in tracker.

Beagle has out-of-process indexing and there are still files (usually 
PowerPoint) that can cause the indexer process to hit an infinite loop, 
crash, etc.  Even if the error isn't fatal it still means that data 
isn't indexed, and that's a bug.

> Out of interest, was tracker's indexing faster than Beagle?

I'm not sure, I didn't watch the timing closely.  If I have time 
tomorrow I'll run both and see.

> > I wholeheartedly agree that the lack of a larger metadata plan is a
> > problem for the platform.  Without anyone using Tracker for this
> > purpose, I think it's premature to approve it.
>
> Well thats chicken and egg!
>
> I cant use it in Epiphany without some approval for either dependency or 
>  getting in the desktop. If the maintainer of Epiphany gives the go 
> ahead it should be allowed in my book...

There's both Tracker and Beagle support in Nautilus and Deskbar, for 
instance.  Applications needn't have a hard dependency to take advantage.

> Not really. There's a ton of stuff you can do in a relational database 
> thats not possible in a dedicated indexer like Lucene  (Eg Extensible 
> metadata, tag database, using it as a common metadata database etc)

It's possible to do these things, although not as easily with a DB. 
This metadata isn't fundamentally any different than the metadata we 
currently store.

> No these will be predfined initially like a Note will have a set of 
> metadata associated with it which can be stored in the DB instead of as 
> a seperate file (aka persistent storage). Anyway this all requires a 
> relational DB to implement.

My gut feeling here is that this sounds pretty limiting if this sort of 
stuff is predefined.  What advantage does an application have in storing 
this in Tracker over a DB itself (or even just XML in a file)?

The use cases here seem very murky to me.

> I take it you dont have a problem with tracker being used as a stand 
> alone metadata DB in conjuction with beagle?

I'm not sure, really.  I don't think it makes sense to run two different 
services for this, and it's not clear to me that if these are separate 
how developers are supposed to use them.  If the user wanted to get a 
piece of metadata, would they use Beagle or Tracker APIs?  To search 
these values, Beagle would have to also index them.  Does it make sense 
to essentially store them twice?  My feeling lately is that these should 
probably be the same thing.

Joe