I am writing a query which is aggregating some data from one database into a separate database.<BR><BR>Basically, I have a query which returns 3 columns and I have a query that returns 1 column.< ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single ... query to limit or refine results. The alternative is often multiple ...

The four are significant SQL ... on multiple types of data stores at once with different query interfaces (such as Hadoop and NoSQL), and to be highly scalable. Drill’s also meant to run queries ...