The function of an Apply Engine may be one of simple replication, data transformation, event processing, source datastore unload or a more sophisticated active/active data replication scenario. The actions performed by an Apply Engine are described by an Engine Script the complexity of which depends entirely on the intended function and business rules required to describe that function.
The most common function performed by an Apply Engine is to process data from one of the Change Data Capture (CDC) agents, applying business rules to transform that data so that it can be applied or efficiently replicated to a Target datastore of any type on any operating platform.
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Determine requirements
Identify the type of the target datastore; the platform the Apply Engine will run on; and finally the data transformations required, if any, to map the source data to the target data structures.
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Prepare Apply Engine Environment
Once the platform and type of target datastore are known, the environment on that platform must be prepared including the installation of Connect CDC SQData and any other components required by the target datastore. Connect CDC SQData will also utilize your existing native TCP/IP network for publishing data captured on one platform to Engines running on any another platform. Factors including performance requirements and network latency should be considered when selecting the location of the system on which the Engine will execute.
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Configure Engine Controller Daemon
The Engine Controller Daemon is the same program, SQDaemon, as the Capture Controller Daemon but provides local and remote management and control of Engines, Utilities and other User agents on the platform where they execute. Precisely recommends using an Engine Controller Daemon to simplify operation including the optional automatic startup of Engine agents following platform restart.
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Create Apply Engine Script
The Apply Engine utilizes a SQL like scripting language capable of a wide range of operations, from replication of identical source and target structures using a single command to complex business rule based transformations. Connect CDC SQData commands and functions provide full procedural control of data filtering, mapping and transformation including manipulation of data at its most elemental level if required.
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End-to-end Component Verification
Confirm successful Change Data Capture through target datastore content validation.
- See Oracle Straight Replication for an sample Apply engine script and the Apply and Replicator Engine References for a full explanation of the capabilities provided by both types of Engine.
- See Add Engine Controller Daemon for an example of the configuration.