Oracle Database Export (exp) Import (imp) Description

Buffer: the buffer for downloading data, in bytes. It is dependent on the operating system by default.
Consistent: the data involved during the download process is read only. The default value is n.
Direct: Use the pass-through method. The default value is n.
Feeback: displays the number of processing records. The default value is 0, that is, it is not displayed.
File: output file. The default value is expdat. dmp.
Filesize: size of the output file. The default value is the maximum value of the operating system.
Indexes: whether to download the index. The default value is n, which indicates the index definition rather than data. exp does not download the index data.
Log: log file. The default value is none. It is displayed in standard output.
Owner: Specifies the downloaded user name.
Query: select a subset of records.
Rows: Indicates whether to download table records.
Tables: List of output table names
Export the entire instance
Exp dbuser/oracle file = oradb. dmp log = oradb. log full = y consistent = y direct = y
The user shall have dba Permissions
Export all objects of a user
Exp dbuser/oracle file = dbuser. dmp log = dbuser. log owner = dbuser buffer = 4096000 feedback = 10000
Export one or more tables
Exp dbuser/oracle file = dbuser. dmp log = dbuser. log tables = table1, table2 buffer = 4096000 feedback = 10000
Export some data of a table
Exp dbuser/oracle file = dbuser. dmp log = dbuser. log tables = table1 buffer = 4096000 feedback = 10000 query = \ "where col1 = \'... \ 'And col2 \ <... \"
Cannot be used for nested tables
Export a table using multiple fixed-size files
Exp dbuser/oracle file = 1.dmp, 2.dmp, 3.dmp ,... Filesize = 1000 m tables = emp buffer = 4096000 feedback = 10000
This method is usually used when the table data volume is large and a single dump file may exceed the limit of the file system.
Pass-through path
Direct = y, replace the buffer option, and the query option is unavailable
Improves download speed
Consistent options
After the export is started, consistent = y freezes updates to the Data Objects of the export operation from other sessions, so as to ensure the consistency of the dump results. However, this process cannot be too long to prevent the rollback segment and the online log consumption from being completed.
Imp
Upload the dmp file downloaded by exp to the database.
Buffer: Upload data buffer, in bytes, which is dependent on the operating system by default
Commit: whether to submit the uploaded records in the data buffer.
Feeback: displays the number of processing records. The default value is 0, that is, it is not displayed.
File: input file. The default value is expdat. dmp.
Filesize: size of the input file. The default value is the maximum value of the operating system.
Fromuser: Specifies the source user
Ignore: whether to ignore the object creation error. The default value is n. It is normal that the object has been created before upload. Therefore, we recommend that you set this option to y.
Indexes: whether to upload an index. The default value is n, which indicates the index definition rather than data. If the index has been created during the upload, this option is invalid even if it is n. imp automatically updates the index data.
Log: log file. The default value is none. It is displayed in standard output.
Rows: whether to upload table records
Tables: List of input table names
Touser: Specify the target user
Import the entire instance
Imp dbuser/oracle file = oradb. dmp log = oradb. log full = y buffer = 4096000 commit = y ignore = y feedback = 10000
Import all objects of a user
Imp dbuser/oracle file = dbuser. dmp log = dbuser. log fromuser = dbuser touser = dbuser2 buffer = 2048000 commit = y ignore = y feedback = 10000
Import one or more tables
Imp dbuser2/oracle file = user. dmp log = user. log tables = table1, table2 fromuser = dbuser touser = dbuser2 buffer = 2048000 commit = y ignore = y feedback = 10000
Import a table using multiple fixed-size files
Imp dbuser/oracle file =\( 1.dmp, 2.dmp, 3.dmp ,... \) Filesize = 1000 m tables = emp fromuser = dbuser touser = dbuser2 buffer = 4096000 commit = y ignore = y feedback = 10000