How to update data only when the data is changed at oracle?

@jasen_gottlieb 

You can achieve data update only when the data is changed by using a trigger in Oracle.

Here is an example of how you can create a trigger to update a column only when the data in that column is changed:

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CREATE TRIGGER update_trigger
AFTER UPDATE OF column_name ON table_name
FOR EACH ROW
BEGIN
  IF :OLD.column_name != :NEW.column_name THEN
    UPDATE table_name
    SET column_name = :NEW.column_name
    WHERE primary_key_column = :NEW.primary_key_column;
  END IF;
END;

In this trigger, the AFTER UPDATE OF clause specifies that the trigger will activate only after an update on the specified column, column_name, in the table_name table. The trigger compares the old and new values of the column and updates only if there is a change.

Make sure to replace column_name, table_name, and primary_key_column with the actual names in your database schema.

Additionally, consider the performance implications of using triggers for this type of operation, as triggers can have an impact on database performance.