2. Change data capture system
Four commonly used methods
- Audit column
- Snapshot comparison
- Log comparison
- trigger
Audit column: Use a field to identify changed data, such as modification time, modification person, etc. Generally, it is necessary to design a trigger mechanism to maintain the audit column during storage or modification.
Snapshot comparison: Use the core column changes to compare to obtain the changed data. You can use some threading methods provided by DBMS, such as the materialized view refresh in Oracle to capture.
Log comparison: Use the log of the parsing database to obtain changes. The more commonly used method is Binlog+Canal of Mysql. Oracle can consider using GoldenGate.
Trigger: A common way in RDBMS systems to process specific logic to capture data when DML statements are executed