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In some scenarios, when we don't need some rows in the table, we need to issue a delete statement to delete it. But sometimes it's not.

If you want to physically delete this data, in traditional table design, we usually add one more field to represent logical deletion.

For example, is_delete, when the application is processing, add is_delete to the where condition to indicate whether the row is actually deleted.

In 12 C, a new feature called row archive is introduced, which allows the database to do these operations automatically. This feature is also known as In-Database Archiving.

SQL > create table employees_test as select * from employees

Table created.

SQL > select count (*) from employees_test where department_id=80

COUNT (*) 34

SQL > alter table employees_test row archival

Table altered.

After row archival is allowed, the system automatically adds a field ORA_ARCHIVE_STATE to indicate the availability of the data.

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