1.2.2 Summary analysis scenario definitions that require no programming

The actions performed in stream data processing are defined by queries that are called summary analysis scenarios. Definitions for these summary analysis scenarios are written in a language called CQL, which is very similar to SQL, the standard language used to manipulate databases. This means that you do not need to create a custom analysis application to create summary analysis scenarios. Summary analysis scenarios can also be modified simply by changing the definition files written in CQL.

Stream data processing actions written in CQL are called queries. In a single summary analysis scenario, multiple queries can be coded.

For example, the following figure shows a summary analysis scenario written in CQL for a temperature monitoring system that has multiple observation sites, each with an assigned ID. The purpose of the query is to summarize and analyze all of the below freezing point data found in the observed data set.

Figure 1-5 Example of using CQL to write a summary analysis scenario

[Figure]

CQL is a general-purpose query language that can be used to specify a wide range of processing. By combining multiple queries, you can define summary analysis scenarios to handle a variety of operations.