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What is change data capture in Oracle?
Change Data Capture efficiently identifies and captures data that has been added to, updated, or removed from, Oracle relational tables, and makes the change data available for use by applications. Change Data Capture is provided as an Oracle database server component with Oracle9i.
What are the two methods of data capture?
The most appropriate data capture method depends on the nature of data to be captured and the application area.
- Manual Keying.
- Nearshore keying.
- OCR (Optical Character Recognition)
- ICR (Intelligent Character Recognition)
- Barcode/ QR recognition.
- Template based intelligent capture.
- IDR (Intelligent Document Recognition)
What makes a good data capture form?
Data capture forms often use boxes or a set amount of spaces and occasionally provide examples too. This is to make sure each field is completed correctly. Data is often entered as a code in a database, for example in the data capture form, Y is used for Yes and N for No.
How does the change data capture cleanup work?
The change data capture cleanup process is responsible for enforcing the retention-based cleanup policy. First, it moves the low endpoint of the validity interval to satisfy the time restriction. Then, it removes expired change table entries. By default, three days of data are retained.
How to determine if a database is enabled for change data capture?
To determine if a database is already enabled, query the is_cdc_enabled column in the sys.databases catalog view. When a database is enabled for change data capture, the cdc schema, cdc user, metadata tables, and other system objects are created for the database.
When to remove a capture instance from a change table?
Allowing the capture mechanism to populate both change tables in tandem means that a transition from one to the other can be accomplished without loss of change data. This can happen any time the two change data capture timelines overlap. When the transition is effected, the obsolete capture instance can be removed.
What is change data capture ( CDC ) in SQL Server?
Applies to: SQL Server (all supported versions) Azure SQL Database Azure SQL Managed Instance Change data capture (CDC) records insert, update, and delete activity that applies to a SQL Server table. This makes the details of the changes available in an easily consumed relational format.