Oracle Database logical backup Import and Export

Logical backup creates a logical copy of the database object and stores it in a binary dump file :. the exported dmp file records are not related to the physical location. The essence of the import is to read the exported binary dump file and restore it to the database for import and export. The common implementation methods are as follows:
When using the Data Pump for export, if you do not directly export the data to a remote database, you must first create a directory object. The directory object is the name directory location on the database server. Because the directory owner is not a database user, therefore, directories are different from tables. directories are not schema object directories that are similar to resources or roles. Their owners are all databases.
Because the data pump does not exist like an independent client program but runs inside the database, the code for creating a directory object is as follows: in a windows environment, in a unix environment, and then authorize an object such as an index for a directory object, only metadata will be exported during export, because it contains a specific physical address related to the storage environment and will be rebuilt during import, files created by a data pump export program are called dump files and one or more dump files may be created during a single data pump export job. All dump files are called dump files 1. the full Database Export mode requires the user to have the EXP_FULL_DATABASE role example: Main Parameters: 2. user Mode: 3. table export Method 4. table space export uses a Data Pump to import data: the imported and exported database objects can be the same database, or different database data pump import programs impdp can be performed as follows: EXP/IMP is a single-threaded Database Import and Export tool based on client sessions. It is not suitable for large-scale database systems.
Compared with exp/imp, imp import has the following advantages: