Oracle CDC Client

Data Collector

The Oracle CDC Client origin processes change data capture (CDC) information provided by Oracle LogMiner redo logs. For information about supported versions, see Supported Systems and VersionsSupported Systems and Versions in the Data Collector documentation.

You might use this origin to perform database replication. You can use a separate pipeline with the JDBC Query Consumer or JDBC Multitable Consumer origin to read existing data. Then start a pipeline with the Oracle CDC Client origin to process subsequent changes.

Oracle CDC Client processes data based on the commit number, in ascending order.

To read the redo logs, Oracle CDC Client requires the LogMiner dictionary. The origin can use the dictionary in redo logs or in an online catalog. When using the dictionary in redo logs, the origin captures and adjusts to schema changes. The origin can also generate events when using redo log dictionaries.

Note: To use Oracle CDC Client, you must enable LogMiner for the database that you want to use and complete the necessary prerequisite tasks. The origin uses JDBC to access the database.

The origin includes CDC and CRUD information in record header attributes so generated records can be easily processed by CRUD-enabled destinations. For an overview of Data Collector changed data processing and a list of CRUD-enabled destinations, see Processing Changed Data.

When you configure Oracle CDC Client, you configure change data capture details, such as the schema and tables to read from, how to read the initial change, the dictionary source location, and the operations to include. You also specify the transaction window and LogMiner session windows to use.

You can configure the origin to buffer records locally or to use database buffers. Before using local buffers, verify that the required resources are available and specify the action to take for uncommitted transactions.

You can specify the behavior when the origin encounters an unsupported data type, and you can configure the origin to pass null values when it receives them from supplemental logging data. When the source database has high-precision timestamps, you can configure the origin to write string values rather than datetime values to maintain the precision.

You can specify JDBC connection information and user credentials. You can also use a connection connection to configure the origin. If the schema was created in a pluggable database, state the pluggable database name. You can configure custom properties that the driver requires.

You can configure advanced connection properties. To use a JDBC version older than 4.0, you specify the driver class name and define a health check query.

The origin can generate events for an event stream. For more information about dataflow triggers and the event framework, see Dataflow Triggers Overview.

When concerned about performance, as when processing very wide tables, you can consider several alternatives to the default origin behavior. You can use the alternate PEG parser or use multiple threads for parsing. Or, you can configure the origin to not parse SQL query statements so you can pass the queries to the SQL Parser processor to be parsed.

For a list of supported operations and a description of generated records, see Parse SQL, Supported Operations, and Generated Records.