Event Sources Event Sources and Event Sinks

Introduction to Oracle CQL 1-15 Oracle CEP relational database table and cache event sources are pull data sources: that is, Oracle CEP polls the event source on arrival of an event on the data stream. For more information, see: ■ Section 1.1.9, Table Event Sources ■ Section 1.1.10, Cache Event Sources

1.1.8.2 Event Sinks

An Oracle CQL event sink connected to a CQL processor is a consumer of query results. In Oracle CEP, the following elements may be event sinks: ■ adapter JMS, HTTP, and file ■ channel ■ processor ■ cache You can associate the same query with more than one event sink and with different types of event sink.

1.1.8.3 Connecting Event Sources and Event Sinks

In Oracle CEP, you define event sources and event sinks using Oracle CEP IDE for Eclipse to create the Event Processing Network EPN as Figure 1–5 shows. In this EPN, adapter PriceAdapter is the event source for channel priceStream; channel priceStream is the event source for Oracle CQL processor filterFanoutProcessor. Similarly, Oracle CQL processor filterFanoutProcessor is the event sink for channel priceStream. Figure 1–5 Event Sources and Event Sinks in the Event Processing Network For more information, see: ■ Section 1.1.1, Streams and Relations ■ Section 18.1, Introduction to Oracle CQL Queries, Views, and Joins ■ Oracle Complex Event Processing Developers Guide for Eclipse

1.1.9 Table Event Sources

Using Oracle CQL, you can access tabular data, including: ■ Section 1.1.9.1, Relational Database Table Event Sources ■ Section 1.1.9.2, XML Table Event Sources ■ Section 1.1.9.3, Function Table Event Sources For more information, see Section 1.1.8, Event Sources and Event Sinks 1-16 Oracle Complex Event Processing CQL Language Reference

1.1.9.1 Relational Database Table Event Sources

Using an Oracle CQL processor, you can specify a relational database table as an event source. You can query this event source, join it with other event sources, and so on. For more information, see Section 18.6, Oracle CQL Queries and Relational Database Tables .

1.1.9.2 XML Table Event Sources

Using the Oracle CQL XMLTABLE clause, you can parse data from an xmltype stream into columns using XPath expressions and conveniently access the data by column name. For more information, see Section 18.2.6, XMLTable Query .

1.1.9.3 Function Table Event Sources

Use the TABLE clause to access, as a relation, the multiple rows returned by a built-in or user-defined function, as an array or Collection type, in the FROM clause of an Oracle CQL query. For more information, see: ■ Section 18.2.7, Function TABLE Query ■ Section 1.1.11, Functions

1.1.10 Cache Event Sources

Using an Oracle CQL processor, you can specify an Oracle CEP cache as an event source. You can query this event source and join it with other event sources using a now window only. For more information, see: ■ Section 1.1.8, Event Sources and Event Sinks