4 ms·
Yes, for example the dual of join (called 'sigma'), which only exists for databases in categorical normal form. There are many academic papers and an open-sour
by wisnesky 7y ago
Yes, for example the dual of join (called 'sigma'), which only exists for databases in categorical normal form. There are many academic papers and an open-source project ('categorical query language') here: http://www.categoricaldata.net http://www.categoricaldata.net.
- twic 7y agoSounds interesting! I had a look, but couldn't find out what sigma does. This is not quite the same level as, say, the PostgreSQL documentation: http://www.categoricaldata.net/help/instancesigma.html http://www.categoricaldata.net/help/instancesigma.html Is there somewhere i can go for a worked example of using sigma?
- wisnesky 7y agoSure, here is an example that uses sigma to compute an equivalence relation: http://cql.conexus.ai/quotient.php http://cql.conexus.ai/quotient.php