Re: [Usability] About virtual folders

[Jamie McCracken <jamiemcc blueyonder co uk>]

Eric Larson wrote:
> On Fri, 2005-09-30 at 18:37 +0100, Jamie McCracken wrote:
>
> > Maurizio Colucci wrote:
> >
> > > Hello,
> > >
> > > I haven't read any discussion, or concrete plan, about virtual folders
> > > a-la Vista. Or labels a-la gmail. Do you like the feature?
> >
> > Yes I am working on this :
> >
> > http://freedesktop.org/wiki/Software/Tracker
> >
> > which if/when integrated in Nautilus or Gnome-VFS will give you VFolder 
> > ability as well as metadata/indexing/thumbnailing on the fly. Tracker is 
> > intended to be a replacement for the defunct Medusa (which was supposed 
> > to give Nautilus vfolder capability).
>
>
> It might be worthwhile to consider using beagle.

By all means. I wrote the freedesktop spec for file metadata(1) to 
encourage both Kat and Beagle to adopt it too. (you really dont wanna 
have two indexers running at the same time!)

The main technical hitch for Beagle is Lucene's single table DB which is 
not scalable for storing hundreds of different metadata (the more 
indexes on a table the slower it becomes to insert stuff and it will 
increase memory consumption dramatically too if lucene keeps its indexes 
in RAM). As a result, I urge Beagle to use Sqlite to store their 
metadata for searching using multiple tables to avoid the "too many 
indexes on a table" problem (though they turned down my suggestion to do 
this a while ago).

THe following table structure for sqlite can store an infinite amount of 
metadata per file whilst only needing 4 indexes (two are primary keys) 
for fast searches:

Create Table Files (
FileID integer not null,
FilePath varchar not null,
FileName varchar not null,
Primary Key (FileID)
);

CREATE UNIQUE INDEX  IndexFiles ON Files (FilePath, FileName);

CREATE TABLE FileMetaData (
FileID INTEGER Not NULL,
MetaDataID INTEGER Not NULL,
MetaDataValue Varchar Not Null,
Primary Key (FileID,MetaDataID)
);

CREATE INDEX IndexFileMetaData ON FileMetaData (MetaDataID, FileID);

Please encourage Beagle to consider this. Tracker's emphasis is on being 
a replacement for Medusa rather than Beagle as such and for providing a 
memory efficient non-bloated search engine/metadata framework for 
systems unable to run mono/beagle (think desktops with only 256MM RAM or 
less or embedded platforms like Maemo) and for those unwilling 
politically/legally to use mono.

(1) http://freedesktop.org/wiki/Standards/shared-filemetadata-spec

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