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Oracle Change Data Capture.pdf
- 1. ORACLE CHANGE DATACAPTURE EXPLAINED- DEVELOPMENT AND TECHNOLOGY What is Oracle Change Data Capture Oracle Change Data Capture is a software pattern that tracks and monitors changes made to a database, based on which businesses can make decisions that put them ahead of their competitors.These changes are primarily used for data identification, integration, and delivery. The benefit is that Change Data Capture boosts warehousing capabilities and speeds up operations across organizations.
- 2. This feature ofthe Oracle Database Management System (DBMS) is an optimized and non-intrusive method for replicating databases. Most importantly, with Oracle Change Data Capture, there is no need to shut down the source database or divest queries from the source to the target database while replicating databases to the cloud. This capability is critical for large data-driven organizations, as system downtime, even for a brief period, can hamper operations badly. Further, with Oracle CDC, data generated after the last replication, also called incremental data, can be extracted and transferred to a destination data warehouse. Oracle Change Data Capture captures and preserves the state of the data through any data storage or data repository, and is limited to a specific data warehouse environment. It can be either an application logic or physical storage in standalone positions or in a combination of the two. Change Data Capture extracts and replicates all changes to the databases in real-time as soon as they are identified in the source databases. Hence, this technology is useful for reducing data warehousing costs while exponentially increasing database speed and performance. ORACLE CHANGE DATA CAPTURE EXPLAINED- DEVELOPMENT AND TECHNOLOGY
- 3. The Progress ofOracle Change Data Capture From Launch The Oracle Change Data Capture product was first launched by Oracle DBMS as an out-of-the-box tool with its 9i version. It could record and monitor changes made to user tables in databases that were then stored in user tables for later use in ETL applications.Whenever required, users could process the changed data and transfer it to target databases or other data warehouses. The technology behind the first version of Oracle CDC was quite simple.Triggers were placed in the source database that were set off whenever any change was identified. However, this technology was found to be too intrusive and complex by DBAs. Based on the feedback, Oracle released a new model of Oracle Change Data Capture with the 10g version and named it Oracle Streams. Streams became very popular among users as databases were not required to be shut down during replication. It used the redo logs of the source database in combination with an in-built replication tool of Oracle Streams. Despite its acceptance, Oracle discontinued Streams as an in-built tool from its 12c version. Users could access this CDC feature in the paid Oracle Golden Gate model of Oracle or use any other CDC product. ORACLE CHANGE DATA CAPTURE EXPLAINED- DEVELOPMENT AND TECHNOLOGY
- 4. Benefits of OracleChange Data Capture • Quick data extraction: Users can quickly extract changes made in real-time. Without Oracle CDC, “Insert” changes cannot be tracked. • Placement of flat files: Flat files that are not required for staging data directly in relational tables can be placed through Oracle Change Data Capture. • User-friendly interface: Oracle CDC has a user-friendly interface that is available through DBMS_LOGMNR_CDC_PUBLISH and DBMS_LOGMNR_CDC_SUBSCRIBE packages. The Oracle Change Data Capture is today an indispensable tool for modern data-driven businesses. ORACLE CHANGE DATA CAPTURE EXPLAINED- DEVELOPMENT AND TECHNOLOGY