Language Selection

English French German Italian Portuguese Spanish

Akonadi, Nepomuk and Strigi explained

Filed under
KDE

Tobias recently blogged about Nepomuk, and from the comments it seems that people are a bit in the dark about what Akonadi, Nepomuk and Strigi actually do and how they interact with each other. So if you want to understand those technologies, read on! This blog post is an attempt to clear things up a bit.

Soprano

Let me start with Soprano. Soprano is a Qt library for accessing semantic storage (RDF). In many ways, Soprano can be compared to the QtSql module, the key difference is that QtSql accesses relational data with SQL as the query language, whereas Soprano accesses semantic data with SPARQL as the query language.

Semantic Data

But what is semantic data, and what is the difference to relational data? You probably all know relational databases, which use tables to store data. Semantic databases, on the other hand, use statements, also sometime referred to as sentences, to store data. Statements consist, just like real-world sentences, of a subject (noun), a predicate (verb) and an object. By storing many sentences in a database, one can create a big network of data. The best way to make this clear is probably by examples, so here are some:

rest here




More in Tux Machines

today's leftovers

'Turbo Boost Max 3.0' and Mesa 17.2.4

  • Turbo Boost Max 3.0 Support For Skylake Fixed With Linux 4.15
    The platform-drivers-x86 updates have been sent in for Linux 4.15 and include a range of improvements for Intel hardware support. One of the bigger items is support for Skylake CPUs with Turbo Boost Max 3.0.
  • Mesa 17.2.4 Graphics Stack Lands for Ubuntu 16.04 LTS and Ubuntu 17.10 Gamers
    Canonical's Timo Aaltonen reports on the availability of the Mesa 17.2.4 open-source graphics drivers stack on the X-SWAT updates PPA for Ubuntu 16.04 LTS and Ubuntu 17.10 systems. Ubuntu systems have always lagged behind the development of the Mesa 3D Graphics Library, the Linux graphics stack containing open-source drivers for Intel, AMD Radeon, and Nvidia GPUs, but they usually catch up with it through a specially crafted PPA (Personal Package Archive) repository that can be easily installed by users.

OSS Leftovers

  • The Future of Marketing Technology Is Headed for an Open-Source Revolution
  • Edging Closer – ODS Sydney
    Despite the fact that OpenStack’s mission statement has not fundamentally changed since the inception of the project in 2010, we have found many different interpretations of the technology through the years. One of them was that OpenStack would be an all-inclusive anything-as-a-service, in a striking parallel to the many different definitions the “cloud” assumed at the time. At the OpenStack Developer Summit in Sydney, we found a project that is returning to its roots: scalable Infrastructure-as-a-Service. It turns out, that resonates well with its user base.
  • Firefox Quantum Now Available on openSUSE Tumbleweed, Linux 4.14 Coming Soon
    Users of the openSUSE Tumbleweed rolling operating system can now update their computers to the latest and greatest Firefox Quantum web browser.
  • Short Delay with WordPress 4.9
    You may have heard WordPress 4.9 is out. While this seems a good improvement over 4.8, it has a new editor that uses codemirror.  So what’s the problem? Well, inside codemirror is jshint and this has that idiotic no evil license. I think this was added in by WordPress, not codemirror itself. So basically WordPress 4.9 has a file, or actually a tiny part of a file that is non-free.  I’ll now have to delay the update of WordPress to hack that piece out, which probably means removing the javascript linter. Not ideal but that’s the way things go.

Red Hat and Fedora Leftovers