CCL: Sybase の問合せ言語

Continuous Computation Language

CCL is the primary event processing language of the Event Stream Processor. ESP projects are defined in CCL.

CCL is based on Structured Query Language (SQL), adapted for event stream processing.

CCL supports sophisticated data selection and calculation capabilities, including features such as: data grouping, aggregations, and joins. However, CCL also includes features that are required to manipulate data during real-time continuous processing, such as windows on data streams, and pattern and event matching.

The key distinguishing feature of CCL is its ability to continuously process dynamic data. A SQL query typically executes only once each time it is submitted to a database server and must be resubmitted every time a user or an application needs to reexecute the query. By contrast, a CCL query is continuous. Once it is defined in the project, it is registered for continuous execution and stays active indefinitely. When the project is running on the ESP Server, a registered query executes each time data arrives from one of its datasources.

Although CCL borrows SQL syntax to define continuous queries, the ESP server does not use an SQL query engine. Instead, it compiles CCL into a highly efficient byte code that is used by the ESP server to construct the continuous queries within the data-flow architecture.

CCL queries are converted to an executable form by the CCL compiler. Compilation is typically performed within Event Stream Processor Studio, but it can also be performed by invoking the CCL compiler from the command line.

http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc01622.0500/doc/html/kes1304454526537.html

注目すべきは次の部分だろうか．

it compiles CCL into a highly efficient byte code that is used by the ESP server to construct the continuous queries within the data-flow architecture

やはり CQ はコンパイルするのが良いと．