Using Oracle Import to recover Database Objects

Lesson 7	Using Import to recover database objects
Objective	Use Import to restore database information.

Using Oracle Import to recover Database Objects

You have seen how to export database objects from your database. Now we will review the use of the Import utility to insert data objects into a database. The database that you insert objects into does not need to be the same database that was used for the extract. For example, many application providers will export a base image of their database to facilitate the installation of their customer databases.

Import modes

As with exports, there are three import modes:

Mode	Description
Table	Will allow you to import a selected table. You must have the appropriate user privileges to import other user's table.
User	Will allow you to import a database object for a specific user.
Full	Will allow you to import all database objects except for those owned by SYS. Users must have `IMP_FULL_DATABASE` role to import a full database export.

Import commands (Legacy Examples)

The following examples use Oracle 8.0.5 on an NT platform.
To run an interactive import session, use the following command:

C:/Oracle/bin>imp80 system/manager

To import data using a parameter file, use the following command:

C:/Oracle/bin>imp80 parfile=import filename

As with Export, you can override parameters in the import file by including them on the command line.
If the user SCOTT had deleted his DEPT table, the following command would restore the DEPT table, and only the DEPT table. The rows=y parameter causes the import to load the data as well as the structure.

C:/Oracle/bin>imp80 scott/tiger tables=dept 
rows=y file=C:\exp01.dmp

Importing incremental, cumulative, and complete export files

Let us say that you have a complete export file, X.dmp; a cumulative export file, C.dmp; and an incremental export file, I.dmp. To import these into a new database properly, you would use the following command:

imp80 system/manager inctype=SYSTEM full=y 
file=I.dmp

This will import all the new system objects into your database from the most recent version of the database. Then you would execute the following series of commands to import the data:

imp80 system/manager inctype=RESTORE full=y 
file=X.dmp

imp80 system/manager inctype=RESTORE full=y 
file=C.dmp

imp80 system/manager inctype=RESTORE full=y 
file=I.dmp

Online help

You can get online help by executing the following command:

C:/Oracle/bin>imp80 help=y

The output from this online help command is shown in the following SlideShow:

This is the first part of the help output
This is the second part of the help output.

Oracle Import Help
The next lesson concludes this module.