Follow this step-by-step guide to install PostgreSQL, load data, connect to a database, and execute SQL queries including table joins PostgreSQL is an open-source, object-relational (also called ...

I have a table that logs a record containing a userid, a fileid and a date, one record inserted every time that file is downloaded.<BR><BR>I want to get the top 10 downloads by count for a given date ...

Query federation is a way to make use of distributed data sources on the Web, including many SPARQL endpoints as well as relational databases. SWObjects makes use of mapping rules represented as ...