path: root/README

INTRODUCTION

Tracker is a powerful desktop-neutral first class object database, tag/metadata database, search tool and indexer. 

Tracker is also extremely fast and super efficient with your systems memory when compared with some other competing frameworks and is by far the fastest and most memory efficient Nautilus search and Deskbar backends currently availble.

It consists of a common object database that allows entities to have an almost infinte number of properties, metadata (both embedded/harvested as well as user definable), a comprehensive database of keywords/tags and links to other entities.

It provides additional features for file based objects including context linking and audit trails for a file object.

It has the ability to index, store, harvest metadata. retrieve and search all types of files and other first class objects.

First class object support includes : Files, Documents, Music, Images, Videos, Playlists*, Notes*, Applications*, Contacts*, Emails*, Conversations*, Appointments*, Tasks*, Bookmarks*, History* and Projects*

(* these services are not currently indexed at the moment but will be in later versions)


All discussion related to tracker happens on the tracker mailing list (http://mail.gnome.org/mailman/listinfo/tracker-list)

More infomation on Tracker can be found at http://freedesktop.org/wiki/Software/Tracker


USE CASES

Tracker is the most powerful open source metadata database and indexer framework currently available and because it is built around a combination indexer and sql database and not a dedicated indexer it has much more powerful use cases:

* Provide search and indexing facilities similiar to those on other systems

* Common database storage for all first class objects (EG a common music/photo/contacts/email/bookmarks/history database) complete with additional metadata and tags/keywords

* Comprehensive one stop solution for all applications needing an object database, powerful search (via RDF Query), first class methods, related metadata and user definable metadata/tags

* Can provide a full semantic desktop with metadata everywhere

* Can provide powerful criteria based searching suitable for creating smart file dialogs and vfolder systems

* Can provide a more intelligent desktop using statistical metadata



NEW CHANGES

* Imporved indexing speed

* Removed libextractor dependency and created a suite of metadata extractors instead

* Redesigned around Sqlite DB and QDBM inverted word index

* New Tracker search tool (GUI)


FEATURES

* Desktop-neutral design (its a freedesktop product built around other freedesktop technologies like DBus and XDGMime but contains no GNOME specific dependencies)

* Very memory efficient and non-leaking (typical RAM usage 4 - 6 MB). Unlike some other indexers, tracker is designed and built to run well on lower memory systems with typically 128MB or 256MB memory. It should even be efficient enough to use on some mobile devices.

* Non-bloated and written in C for maximum efficiency.

* Small size and minimal dependencies makes it easy to bundle into various distro's including live cds.

* Fast indexing and unobtrusive - no need to index stuff overnight. Tracker runs at nice+10 so it should have a minimal impact on your system. 

* Implements the freedesktop specification for metadata http://freedesktop.org/wiki/Standards/shared-filemetadata-spec

* Extracts embedded File, Image, Document and Audio type metadata from files.

* Supports the WC3's RDF Query syntax for querying metadata

* Provides support for both free text search (like Beagle/Google) as well as structured searches using RDF Query

* Respond in real time to file system changes to keep its metadata database up to date and in synch

* Fully extendable with custom metadata - you can store, retrieve, register and search via RDF Query all your own custom metadata

* Can extract a file's contents as plain text and index them

* Provides text filters for PDF, MS Office, OpenOffice (all versions), HTML and PS files.

* Can provide thumbnailing on the fly



INSTALLATION (from source):




Run time dependencies (also needed for build) :

Sqlite 3.2+

libdbus (0.50 +)

dbus-glib bndings (0.50 +)

glib (2.6+)

zlib

GMime


Additional recommended packages:

wv (1.0.2+)
poppler (pdftotext)
libvorbis
GTK and Gnome stack for GUI tools


COMPILATION

To compile Tracker uses the following commands :

./configure --prefix=/usr
make
sudo make install

If you install using any other prefix then you might have problems with files not being installed correctly.

(You may need to copy and amend the dbus service file to the correct directory and/or might need to update ld_conf if you install into non standard directories.)

Notes to build tracker on Solaris

To compile Tracker with GCC on Solaris uses the following commands :
./configure --prefix=/usr --with-pic CFLAGS=-D_POSIX_PTHREAD_SEMANTICS
make
login as root
make install

To compile Tracker with SUN Studio on Solaris uses the following commands, because there are some problems to compile exiv2 using SUN C++ compiler:
./configure --prefix=/usr --with-pic --disable-warnings --disable-exiv2 CFLAGS=-D_POSIX_PTHREAD_SEMANTICS
make
login as root
make install



Compile Options

Tracker has several compiler options to enable/disable certain features. The following is available (all options should be passed as command line parameters to autogen.sh EG ./autogen.sh --disable-fam)

--disable-fam : this option omits support of FAM/GAMIN with tracker

--disable-inotify : this option omits support for inotify with tracker



RUNNING TRACKER


To run tracker, you need to manually start the tracker daemon trackerd. By default trackerd will index your entire home directory.

You can also pass a directory root to be indexed as a command line parameter if you dont want your entire home directory indexed. EG

"trackerd /home/jamie/Documents"

You can disable indexing by passing --disable-indexing

You can enable a low memory usage mode (recommended for machines with less than 256MB of RAM) by passing --enable-low-memory

You can enable turbo indexing by passing --turbo

You can specify directory roots not to be watched or indexed by passing  --ignore-dirs=dir1 for each directory root

You can make sure that tracker only indexes a subset of your home directory and also specify folders not in your home directory by editing the tracker.cfg file in ~/.Tracker (which is created when you first run trackerd) and setting WatchDirectoryRoots to a semicolon delimited list of directories (full path required!) 

EG: 

WatchDirectoryRoots=directory1;directory2;directory3

On the first run, Tracker will automatically create a new database and start populating it with metadata by browsing through the user's home directory (or the root folder(s) specified).

On subsequent runs, Tracker will start up much much faster and will only ever incrementally index files (IE files that have changed since last index).

If installed correctly, the tracker daemon (trackerd) can also be started automatically via Dbus activation.


Tracker And Nautilus Search

Once you have installed Tracker and have some indexed contents, you should now compile Nautilus (ver 2.13.4 or higher) which should auto detect that tracker is installed and automatically compile in tracker support. You are now ready to appreciate a powerful and super efficient c based indexer in all its glory... happy hunting!

To make sure trackerd always start when you login to Gnome, you will need to add it to Gnome-session (select sessions from preferences menu, select startup program tab and then add /usr/bin/trackerd). For non-gnome installations, see the desktop docs for how to auto start an application for your particular desktop.

Tracker and Deskbar applet

Tracker is also integrated in GNOME's deskbar applet. Please see that applet for more info.



COMMAND LINE TOOLS

Tracker comes with a number of command line apps that you can use:

"tracker-tag" for setting and searching tags/keywords

"tracker-extract FILE" - this extracts embedded metadata from FILE and prints to stdout

"tracker-search SEARCHTERM" - this perfoms a google like search using SEARCHTERM to retrieve all matching files where SEARCHTERM appears in any searchable metadata

"tracker-query" - this reads an RDF Query that specifies the search criteria for various fields. It prints to STDOUT all matching files. You can see some example queries in the RDF-Query-examples folder. You can run the examples as "tracker-query < RDFFILE"