An activation query is a query that returns a list of identifiers that relate to specific individuals.

For example, an activation query might return a list of email addresses to contact, or a list of customer numbers to target with an offer.

You can only use an activation query if you have created, or have been given permission to reference a Dataset that contains Export columns. 

The simplest activation query comprises of two clauses. The SELECT clause defines what you are trying to achieve in terms of information gained, and the FROM clause defines the audience you are intending to learn about. The example below would return a list of output data, the type of identifier, from the Dataset referenced.

SELECT 
  Dataset.outputcolumn

FROM Dataset

This query would return the overlap of the two Datasets - a list of email addresses of the individuals who appear in both the Dataset exporting the data (ID) and anther Dataset (A).

SELECT 
  ID.email

FROM ID INTERSECT A

If you want to, you can filter this audience using the attribute data held in the Dataset. A The query below would return the email addresses of the individuals in the overlap who have an income greater than £30,000 and are aged 30 or below.

SELECT 
  ID.email

FROM ID INTERSECT A

WHERE 
  Income > 30000
  Age <= 30

To build, test and run queries, try using the Query Tool.