Filtering

Use the WHERE clause in your CCL query to filter data to be processed by the derived elements (streams, windows, or delta streams).

Using the WHERE clause and a filter expression, you can filter which incoming data is accepted by your derived elements. The WHERE clause restricts the data captured by the SELECT clause, reducing the number of results generated. Only data matching the value specified in the WHERE clause is sent to your derived elements.

The output of your derived element consists of a subset of records from the input. Each input record is evaluated against the filter expression. If a filter expression evaluates to false (0), the record does not become part of the derived element.

This example creates a new window, IBMTrades, where its rows are any of the result rows from Trades that have the symbol "IBM":

CREATE WINDOW IBMTrades
	PRIMARY KEY DEDUCED
	AS SELECT * FROM Trades WHERE Symbol = 'IBM';