Using the Export and Import Utilities for Supplemental Database Protection

• Using Import

• Using Export

See Also: Both the Export and Import utilities are described in detail in the Oracle7 Server Utilities guide.

Using Export

Warning: If you use Export to backup, all data must be exported in a logically consistent way so that the backup reflects a single point in time. No one should make changes to the database while the Export takes place. Ideally, you should run the database in restricted mode while you export the data, so no regular users can access the data.

Table 23 - 1 lists available export modes.

Mode	Description
User	exports all objects owned by a user
Table	exports all or specific tables owned by a user
Full Database	exports all objects of the database

Table 23 - 1. Export Modes

Following are descriptions of Export types:

Incremental Export	Only database data that has changed since the last incremental, cumulative, or complete export is exported. An incremental export exports the object's definition and all its data. Incremental exports are typically performed more often than cumulative or complete reports.
	For example, if tables A, B, and C exist, and only table A's information has been modified since the last incremental export, only table A is exported.
Cumulative Exports	Only database data that has been changed since the last cumulative or complete export is exported.
	Perform this type of export on a limited basis, such as once a week, to condense the information contained in numerous incremental exports.
	For example, if tables A, B, and C exist, and only table A's and table B's information has been modified since the last cumulative export, only the changes to tables A and B are exported.
Complete Exports	All database data is exported.
	Perform this type of export on a limited basis, such as once a month, to export all data contained in a database.

Using Import

To recover a database using Export files and the Import utility:

• Re-create the database structure, including all tablespaces and users

• Import the appropriate Export files to restore the database to the most current state possible. Depending on how your Export schedule is performed, imports of varying degrees will be necessary to restore a database.

Figure 23 - 1. A Typical Export Schedule

A complete export was taken on Day 1, a cumulative export was taken every week, and incremental exports were taken daily.

1. Recreate the database, including all tablespaces and users.

2. Import the complete database export taken on Day 1.

3. Import the cumulative database export taken on Day 7.

4. Import the incremental database exports taken on Days 8, 9, and 10.