Asking questions to data in the humanities: right, correct, efficient (Introducing and comparing XQuery, SQL, SPARQL for data from the humanities)

The workshop "Asking questions to data in the humanities: right, correct, efficient" provides an introduction to XQuery, SQL and graph databases from the digital humanities user's perspective. The amount of data in the digital humanities and its complexity is growing continuously. Modern database storage and  access technologies are needed to handle this data. This course will give an introduction to three relevant technologies: relational databases and SQL, XQuery for XML-formatted data, and graph databases for highly-interconnected data. 
                        
Relational databases organize their data in simple tables. SQL is the standard query language to search for and extract data from the database. The technology is mature, there are many excellent database systems available, most programming languages and application programs provide easy access to relational databases.
                        
XML is a language to describe the structure of documents as a hierarchy. XQuery is the standard language to query XML single documents or document collections to search for and extract content from these documents. XML is used for large corpora of text, it is supported by many programming languages, there are numerous application programs and editors for XML data, and it is often used in web-based environments.
                        
Graph databases are a relatively new development. Here, data is seen as information nodes, and the nodes are linked via named arcs. Graphs are highly dynamic and thus well suited in the exploration phase when working with corpora.                        

For the introduction to these technologies, we provided sample data, which also allowed us to compare the different query methods by using the same underlying  information in all paradigms. In course projects, participants worked with sample data provided by us or their own data. By looking at the data, we discussed ways of asking questions to the data and then try to express them in the query language(s) .