Processing Aggregate Queries over Continuous Data Streams Johannes Gehrke, Cornell University In this talk, I will describe techniques for giving approximate answers ...

Count queries are probably the most-used aggregate queries in a relational database. Counting is a fundamental operation required for many CRUD applications like sorting, pagination, and searching.

When working with address data, you may encounter situations where you need to merge multiple columns, such as address, town, and postcode, into a single column. Power Query makes this task a breeze.