Export Parameters:
BUFFER
Default: operating system-dependent. See your Oracle operating system-specific documentation to determine the default value for this parameter.
Specifies the size, in bytes, of the buffer used to fetch rows. As a result, this parameter determines the maximum number of rows in an array fetched by Export. Use the following formula to calculate the buffer size:
buffer_size = rows_in_array * maximum_row_size
If you specify zero, the Export utility fetches only one row at a time.
Tables with columns of type LONG, LOB, BFILE, REF, ROWID, LOGICAL ROWID, or DATE are fetched one row at a time.
Note:
The BUFFER parameter applies only to conventional path Export. It has no effect on a direct path Export.
Example: Calculating Buffer Size
This section shows an example of how to calculate buffer size.
The following table is created:
CREATE TABLE sample (name varchar(30), weight number);
The maximum size of the name column is 30, plus 2 bytes for the indicator. The maximum size of the weight column is 22 (the size of the internal representation for Oracle numbers), plus 2 bytes for the indicator.
Therefore, the maximum row size is 56 (30+2+22+2).
To perform array operations for 100 rows, a buffer size of 5600 should be specified.
COMPRESS
Default: y
Specifies how Export and Import manage the initial extent for table data.
The default, COMPRESS=y, causes Export to flag table data for consolidation into one initial extent upon Import. If extent sizes are large (for example, because of the PCTINCREASE parameter), the allocated space will be larger than the space required to hold the data.
If you specify COMPRESS=n, Export uses the current storage parameters, including the values of initial extent size and next extent size. The values of the parameters may be the values specified in the CREATE TABLE or ALTER TABLE statements or the values modified by the database system. For example, the NEXT extent size value may be modified if the table grows and if the PCTINCREASE parameter is nonzero.
Note:
Although the actual consolidation is performed upon import, you can specify the COMPRESS parameter only when you export, not when you import. The Export utility, not the Import utility, generates the data definitions, including the storage parameter definitions. Therefore, if you specify COMPRESS=y when you export, you can import the data in consolidated form only.
Note:
LOB data is not compressed. For LOB data, values of initial extent size and next extent size at the time of export are used.
CONSISTENT
Default: n
Specifies whether or not Export uses the SET TRANSACTION READ ONLY statement to ensure that the data seen by Export is consistent to a single point in time and does not change during the execution of the exp command. You should specify CONSISTENT=y when you anticipate that other applications will be updating the target data after an export has started.
If you use CONSISTENT=n, each table is usually exported in a single transaction. However, if a table contains nested tables, the outer table and each inner table are exported as separate transactions. If a table is partitioned, each partition is exported as a separate transaction.
Therefore, if nested tables and partitioned tables are being updated by other applications, the data that is exported could be inconsistent. To minimize this possibility, export those tables at a time when updates are not being done.
Table 1-2 shows a sequence of events by two users: user1 exports partitions in a table and user2 updates data in that table.
Table 1-2 Sequence of Events During Updates by Two Users
TIme Sequence User1 User2
1
Begins export of TAB:P1
No activity
2
No activity
Updates TAB:P2
Updates TAB:P1
Commits transaction
3
Ends export of TAB:P1
No activity
4
Exports TAB:P2
No activity
If the export uses CONSISTENT=y, none of the updates by user2 are written to the export file.
If the export uses CONSISTENT=n, the updates to TAB:P1 are not written to the export file. However, the updates to TAB:P2 are written to the export file because the update transaction is committed before the export of TAB:P2 begins. As a result, the user2 transaction is only partially recorded in the export file, making it inconsistent.
If you use CONSISTENT=y and the volume of updates is large, the rollback segment usage will be large. In addition, the export of each table will be slower because the rollback segment must be scanned for uncommitted transactions.
Keep in mind the following points about using CONSISTENT=y:
* CONSISTENT=y is unsupported for exports that are performed when you are connected as user SYS or you are using AS SYSDBA, or both.
* Export of certain metadata may require the use of the SYS schema within recursive SQL. In such situations, the use of CONSISTENT=y will be ignored. Oracle Corporation recommends that you avoid making metadata changes during an export process in which CONSISTENT=y is selected.
* To minimize the time and space required for such exports, you should export tables that need to remain consistent separately from those that do not.
For example, export the emp and dept tables together in a consistent export, and then export the remainder of the database in a second pass.
* A "snapshot too old" error occurs when rollback space is used up, and space taken up by committed transactions is reused for new transactions. Reusing space in the rollback segment allows database integrity to be preserved with minimum space requirements, but it imposes a limit on the amount of time that a read-consistent image can be preserved.
If a committed transaction has been overwritten and the information is needed for a read-consistent view of the database, a "snapshot too old" error results.
To avoid this error, you should minimize the time taken by a read-consistent export. (Do this by restricting the number of objects exported and, if possible, by reducing the database transaction rate.) Also, make the rollback segment as large as possible.
See Also:
OBJECT_CONSISTENT
CONSTRAINTS
Default: y
Specifies whether or not the Export utility exports table constraints.
DIRECT
Default: n
Specifies whether you use direct path or conventional path Export.
Specifying DIRECT=y causes Export to extract data by reading the data directly, bypassing the SQL command-processing layer (evaluating buffer). This method can be much faster than a conventional path Export.
For information about direct path Exports, including security and performance considerations, see Invoking a Direct Path Export.
FEEDBACK
Default: 0 (zero)
Specifies that Export should display a progress meter in the form of a period for n number of rows exported. For example, if you specify FEEDBACK=10, Export displays a period each time 10 rows are exported. The FEEDBACK value applies to all tables being exported; it cannot be set on a per-table basis.
FILE
Default: expdat.dmp
Specifies the names of the export files. The default extension is .dmp, but you can specify any extension. Because Export supports multiple export files (see the parameter FILESIZE), you can specify multiple filenames to be used. For example:
exp scott/tiger FILE = dat1.dmp, dat2.dmp, dat3.dmp FILESIZE=2048
When Export reaches the value you have specified for the maximum FILESIZE, Export stops writing to the current file, opens another export file with the next name specified by the FILE parameter, and continues until complete or the maximum value of FILESIZE is again reached. If you do not specify sufficient export filenames to complete the export, Export will prompt you to provide additional filenames.
FILESIZE
Default: Data is written to one file until the maximum size, as specified in Table 1-3, is reached.
Export supports writing to multiple export files, and Import can read from multiple export files. If you specify a value (byte limit) for the FILESIZE parameter, Export will write only the number of bytes you specify to each dump file.
When the amount of data Export must write exceeds the maximum value you specified for FILESIZE, it will get the name of the next export file from the FILE parameter (see FILE for more information) or, if it has used all the names specified in the FILE parameter, it will prompt you to provide a new export filename. If you do not specify a value for FILESIZE (note that a value of 0 is equivalent to not specifying FILESIZE), then Export will write to only one file, regardless of the number of files specified in the FILE parameter.
Note:
If the space requirements of your export file exceed the available disk space, Export will abort, and you will have to repeat the Export after making sufficient disk space available.
The FILESIZE parameter has a maximum value equal to the maximum value that can be stored in 64 bits.
Table 1-3 shows that the maximum size for dump files depends on the operating system you are using and on the release of the Oracle database server that you are using.
Table 1-3 Maximum Size for Dump Files
Operating System Release of Oracle Server Maximum Size
Any
Prior to 8.1.5
2 gigabytes
32-bit
8.1.5
2 gigabytes
64-bit
8.1.5 and later
Unlimited
32-bit with 32-bit files
Any
2 gigabytes
32-bit with 64-bit files
8.1.6 and later
Unlimited
Note:
The maximum value that can be stored in a file is dependent on your operating system. You should verify this maximum value in your Oracle operating system-specific documentation before specifying FILESIZE. You should also ensure that the file size you specify for Export is supported on the system on which Import will run.
The FILESIZE value can also be specified as a number followed by KB (number of kilobytes). For example, FILESIZE=2KB is the same as FILESIZE=2048. Similarly, MB specifies megabytes (1024 * 1024) and GB specifies gigabytes (1024**3). B remains the shorthand for bytes; the number is not multiplied to obtain the final file size (FILESIZE=2048B is the same as FILESIZE=2048).
FLASHBACK_SCN
Default: none
Specifies the system change number (SCN) that Export will use to enable flashback. The export operation is performed with data consistent as of this specified SCN.
See Also:
Oracle9i Application Developer's Guide - Fundamentals for more information about using flashback
FLASHBACK_TIME
Default: none
Specifies a time. Export finds the SCN that most closely matches the specified time. This SCN is used to enable flashback. The export operation is performed with data consistent as of this SCN.
See Also:
Oracle9i Application Developer's Guide - Fundamentals for more information about using flashback
FULL
Default: n
Indicates that the Export is a full database mode Export (that is, it exports the entire database). Specify FULL=y to export in full database mode. You need to have the EXP_FULL_DATABASE role to export in this mode.
GRANTS
Default: y
Specifies whether or not the Export utility exports object grants. The object grants that are exported depend on whether you use full database mode or user mode. In full database mode, all grants on a table are exported. In user mode, only those granted by the owner of the table are exported. System privilege grants are always exported.
HELP
Default: none
Displays a description of the Export parameters. Enter exp help=y on the command line to invoke it.
INDEXES
Default: y
Specifies whether or not the Export utility exports indexes.
LOG
Default: none
Specifies a filename to receive informational and error messages. For example:
exp SYSTEM/password LOG=export.log
If you specify this parameter, messages are logged in the log file and displayed to the terminal display.
OBJECT_CONSISTENT
Default: n
Specifies whether or not the Export utility uses the SET TRANSACTION READ ONLY statement to ensure that the data exported is consistent to a single point in time and does not change during the export. If OBJECT_CONSISTENT is set to y, each object is exported in its own read-only transaction, even if it is partitioned. In contrast, if you use the CONSISTENT parameter, then there is only one read-only transaction.
See Also:
CONSISTENT
OWNER
Default: none
Indicates that the Export is a user-mode Export and lists the users whose objects will be exported. If the user initiating the export is the DBA, multiple users may be listed.
PARFILE
Default: none
Specifies a filename for a file that contains a list of Export parameters. For more information on using a parameter file, see Invoking Export.
QUERY
Default: none
This parameter allows you to select a subset of rows from a set of tables when doing a table mode export. The value of the query parameter is a string that contains a WHERE clause for a SQL SELECT statement that will be applied to all tables (or table partitions) listed in the TABLE parameter.
For example, if user scott wants to export only those employees whose job title is SALESMAN and whose salary is less than 1600, he could do the following (this example is UNIX-based):
exp scott/tiger TABLES=emp QUERY=\"WHERE job=\'SALESMAN\' and sal \<1600\"
Note:
Because the value of the QUERY parameter contains blanks, most operating systems require that the entire strings WHERE job=\'SALESMAN\' and sal\<1600 be placed in double quotation marks or marked as a literal by some method. Operating system reserved characters also need to be preceded by an escape character. See your Oracle operating system-specific documentation for information about special and reserved characters on your system.
When executing this query, Export builds a SQL SELECT statement similar to the following:
SELECT * FROM emp WHERE job='SALESMAN' and sal <1600;
The values specified for the QUERY parameter are applied to all tables (or table partitions) listed in the TABLE parameter. For example, the following statement will unload rows in both emp and bonus that match the query:
exp scott/tiger TABLES=emp,bonus QUERY=\"WHERE job=\'SALESMAN\' and sal\<1600\"
Again, the SQL statements that Export executes are similar to the following:
SELECT * FROM emp WHERE job='SALESMAN' and sal <1600;
SELECT * FROM bonus WHERE job='SALESMAN' and sal <1600;
If a table is missing the columns specified in the QUERY clause, an error message will be produced, and no rows will be exported for the offending table.
Restrictions
* The parameter QUERY cannot be specified for full, user, or tablespace mode exports.
* The parameter QUERY must be applicable to all specified tables.
* The parameter QUERY cannot be specified in a direct path export (DIRECT=y)
* The parameter QUERY cannot be specified for tables with inner nested tables.
* You cannot determine from the contents of the export file whether the data is the result of a QUERY export.
RECORDLENGTH
Default: operating system-dependent
Specifies the length, in bytes, of the file record. The RECORDLENGTH parameter is necessary when you must transfer the export file to another operating system that uses a different default value.
If you do not define this parameter, it defaults to your platform-dependent value for buffer size. For more information about the buffer size default value, see your Oracle operating system-specific documentation.
You can set RECORDLENGTH to any value equal to or greater than your system's buffer size. (The highest value is 64 KB.) Changing the RECORDLENGTH parameter affects only the size of data that accumulates before writing to the disk. It does not affect the operating system file block size.
Note:
You can use this parameter to specify the size of the Export I/O buffer.
See your Oracle operating system-specific documentation to determine the proper value or to create a file with a different record size.
RESUMABLE
Default: n
The RESUMABLE parameter is used to enable and disable resumable space allocation. Because this parameter is disabled by default, you must set RESUMABLE=y in order to use its associated parameters, RESUMABLE_NAME and RESUMABLE_TIMEOUT.
See Also:
* Oracle9i Database Concepts
* Oracle9i Database Administrator's Guide for more information about resumable space allocation
RESUMABLE_NAME
Default: 'User USERNAME (USERID), Session SESSIONID, Instance INSTANCEID'
The value for this parameter identifies the statement that is resumable. This value is a user-defined text string that is inserted in either the USER_RESUMABLE or DBA_RESUMABLE view to help you identify a specific resumable statement that has been suspended.
This parameter is ignored unless the RESUMABLE parameter is set to y to enable resumable space allocation.
RESUMABLE_TIMEOUT
Default: 7200 seconds (2 hours)
The value of the parameter specifies the time period during which an error must be fixed. If the error is not fixed within the timeout period, execution of the statement is aborted.
This parameter is ignored unless the RESUMABLE parameter is set to y to enable resumable space allocation.
ROWS
Default: y
Specifies whether or not the rows of table data are exported.
STATISTICS
Default: ESTIMATE
Specifies the type of database optimizer statistics to generate when the exported data is imported. Options are ESTIMATE, COMPUTE, and NONE. See the Import parameter STATISTICS and Importing Statistics.
In some cases, Export will place the precalculated statistics in the export file as well as the ANALYZE statements to regenerate the statistics.
However, the precalculated optimizer statistics will not be used at export time if a table has columns with system-generated names.
The precalculated optimizer statistics are flagged as questionable at export time if:
* There are row errors while exporting
* The client character set or NCHAR character set does not match the server character set or NCHAR character set
* A QUERY clause is specified
* Only certain partitions or subpartitions are exported
Note:
Specifying ROWS=n does not preclude saving the precalculated statistics in the Export file. This allows you to tune plan generation for queries in a nonproduction database using statistics from a production database.
See Also:
Oracle9i Database Concepts
TABLES
Default: none
Specifies that the Export is a table-mode Export and lists the table names and partition and subpartition names to export. You can specify the following when you specify the name of the table:
* schemaname specifies the name of the user's schema from which to export the table or partition. The schema names ORDSYS, MDSYS, CTXSYS, and ORDPLUGINS are reserved by Export.
* tablename specifies the name of the table or tables to be exported. Table-level export lets you export entire partitioned or nonpartitioned tables. If a table in the list is partitioned and you do not specify a partition name, all its partitions and subpartitions are exported.
The table name can contain any number of '%' pattern matching characters, which can each match zero or more characters in the table name against the table objects in the database. All the tables in the relevant schema that match the specified pattern are selected for export, as if the respective table names were explicitly specified in the parameter.
* partition_name indicates that the export is a partition-level Export. Partition-level Export lets you export one or more specified partitions or subpartitions within a table.
The syntax you use to specify the preceding is in the form:
schemaname.tablename:partition_name
schemaname.tablename:subpartition_name
If you use tablename:partition_name, the specified table must be partitioned, and partition_name must be the name of one of its partitions or subpartitions. If the specified table is not partitioned, the partition_name is ignored and the entire table is exported.
See Example Export Session Using Partition-Level Export for several examples of partition-level exports.
Note:
Some operating systems, such as UNIX, require that you use escape characters before special characters, such as a parenthesis, so that the character is not treated as a special character. On UNIX, use a backslash (\) as the escape character, as shown in the following example:
TABLES=\(emp,dept\)
Table Name Restrictions
The following restrictions apply to table names:
* By default, table names in a database are stored as uppercase. If you have a table name in mixed-case or lowercase, and you want to preserve case-sensitivity for the table name, you must enclose the name in quotation marks. The name must exactly match the table name stored in the database.
Some operating systems require that quotation marks on the command line be preceded by an escape character. The following are examples of how case-sensitivity can be preserved in the different Export modes.
o In command-line mode:
TABLES='\"Emp\"'
o In interactive mode:
Table(T) to be exported: "Emp"
o In parameter file mode:
TABLES='"Emp"'
* Table names specified on the command line cannot include a pound (#) sign, unless the table name is enclosed in quotation marks. Similarly, in the parameter file, if a table name includes a pound (#) sign, the Export utility interprets the rest of the line as a comment, unless the table name is enclosed in quotation marks.
For example, if the parameter file contains the following line, Export interprets everything on the line after emp# as a comment and does not export the tables dept and mydata:
TABLES=(emp#, dept, mydata)
However, given the following line, the Export utility exports all three tables because emp# is enclosed in quotation marks:
TABLES=("emp#", dept, mydata)
Note:
Some operating systems require single quotation marks rather than double quotation marks, or the reverse; see your Oracle operating system-specific documentation. Different operating systems also have other restrictions on table naming.
For example, the UNIX C shell attaches a special meaning to a dollar sign ($) or pound sign (#) (or certain other special characters). You must use escape characters to get such characters in the name past the shell and into Export.
For a TABLES parameter that specifies multiple schema.tablename:(sub)partition_name arguments, Export attempts to purge duplicates before processing the list of objects.
TABLESPACES
Default: none
The TABLESPACES parameter specifies that all tables in the tablespace be exported to the Export dump file. This includes all tables contained in the list of tablespaces and all tables that have a partition located in the list of tablespaces. Indexes are exported with their tables, regardless of where the index is stored.
You must have the EXP_FULL_DATABASE role to use TABLESPACES to export all tables in the tablespace.
When TABLESPACES is used in conjunction with TRANSPORT_TABLESPACE=y, you can specify a limited list of tablespaces to be exported from the database to the export file.
TRANSPORT_TABLESPACE
Default: n
When specified as y, this parameter enables the export of transportable tablespace metadata.
See Also:
* Transportable Tablespaces
* Oracle9i Database Administrator's Guide
* Oracle9i Database Concepts
TRIGGERS
Default: y
Specifies whether or not the Export utility exports triggers.
TTS_FULL_CHECK
Default: FALSE
When TTS_FULL_CHECK is set to TRUE, Export verifies that a recovery set (set of tablespaces to be recovered) has no dependencies (specifically, IN pointers) on objects outside the recovery set, and vice versa.
USERID (username/password)
Default: none
Specifies the username/password (and optional connect string) of the user performing the export. If you omit the password, Export will prompt you for it.
USERID can also be:
username/password AS SYSDBA
or
username/password@instance AS SYSDBA
If you connect as user SYS, you must also specify AS SYSDBA in the connect string. Your operating system may require you to treat AS SYSDBA as a special string, in which case the entire string would be enclosed in quotation marks. See Invoking Export As SYSDBA for more information.
See Also:
* Oracle9i Heterogeneous Connectivity Administrator's Guide
* The user's guide for your Oracle Net protocol for information about specifying the @connect_string for Oracle Net
VOLSIZE
Specifies the maximum number of bytes in an export file on each volume of tape.
The VOLSIZE parameter has a maximum value equal to the maximum value that can be stored in 64 bits. See your Oracle operating system-specific documentation for more information.
The VOLSIZE value can be specified as a number followed by KB (number of kilobytes). For example, VOLSIZE=2KB is the same as VOLSIZE=2048. Similarly, MB specifies megabytes (1024 * 1024) and GB specifies gigabytes (1024**3). B remains the shorthand for bytes; the number is not multiplied to get the final file size (VOLSIZE=2048B is the same as VOLSIZE=2048).
Import Parameters:
BUFFER
Default: operating system-dependent
The integer specified for BUFFER is the size, in bytes, of the buffer through which data rows are transferred.
BUFFER determines the number of rows in the array inserted by Import. The following formula gives an approximation of the buffer size that inserts a given array of rows:
buffer_size = rows_in_array * maximum_row_size
For tables containing LONG, LOB, BFILE, REF, ROWID, UROWID, or DATE columns, rows are inserted individually. The size of the buffer must be large enough to contain the entire row, except for LOB and LONG columns. If the buffer cannot hold the longest row in a table, Import attempts to allocate a larger buffer.
Note:
See your Oracle operating system-specific documentation to determine the default value for this parameter.
CHARSET
This parameter applies to Oracle version 5 and 6 export files only. Use of this parameter is not recommended. It is provided only for compatibility with previous versions. Eventually, it will no longer be supported. See The CHARSET Parameter if you still need to use this parameter.
COMMIT
Default: n
Specifies whether Import should commit after each array insert. By default, Import commits only after loading each table, and Import performs a rollback when an error occurs, before continuing with the next object.
If a table has nested table columns or attributes, the contents of the nested tables are imported as separate tables. Therefore, the contents of the nested tables are always committed in a transaction distinct from the transaction used to commit the outer table.
If COMMIT=n and a table is partitioned, each partition and subpartition in the Export file is imported in a separate transaction.
Specifying COMMIT=y prevents rollback segments from growing inordinately large and improves the performance of large imports. Specifying COMMIT=y is advisable if the table has a uniqueness constraint. If the import is restarted, any rows that have already been imported are rejected with a recoverable error.
If a table does not have a uniqueness constraint, Import could produce duplicate rows when you reimport the data.
For tables containing LONG, LOB, BFILE, REF, ROWID, UROWID, or DATE columns, array inserts are not done. If COMMIT=y, Import commits these tables after each row.
COMPILE
Default: y
Specifies whether or not Import should compile packages, procedures, and functions as they are created.
If COMPILE=n, these units are compiled on their first use. For example, packages that are used to build domain indexes are compiled when the domain indexes are created.
See Also:
Importing Stored Procedures, Functions, and Packages
CONSTRAINTS
Default: y
Specifies whether or not table constraints are to be imported. The default is to import constraints. If you do not want constraints to be imported, you must set the parameter value to n.
Note that primary key constraints for index-organized tables (IOTs) and object tables are always imported.
DATAFILES
Default: none
When TRANSPORT_TABLESPACE is specified as y, use this parameter to list the datafiles to be transported into the database.
See Also:
TRANSPORT_TABLESPACE
DESTROY
Default: n
Specifies whether or not the existing datafiles making up the database should be reused. That is, specifying DESTROY=y causes Import to include the REUSE option in the datafile clause of the CREATE TABLESPACE statement, which causes Import to reuse the original database's datafiles after deleting their contents.
Note that the export file contains the datafile names used in each tablespace. If you specify DESTROY=y and attempt to create a second database on the same system (for testing or other purposes), the Import utility will overwrite the first database's datafiles when it creates the tablespace. In this situation you should use the default, DESTROY=n, so that an error occurs if the datafiles already exist when the tablespace is created. Also, when you need to import into the original database, you will need to specify IGNORE=y to add to the existing datafiles without replacing them.
Caution:
If datafiles are stored on a raw device, DESTROY=n does not prevent files from being overwritten.
FEEDBACK
Default: 0 (zero)
Specifies that Import should display a progress meter in the form of a period for n number of rows imported. For example, if you specify FEEDBACK=10, Import displays a period each time 10 rows have been imported. The FEEDBACK value applies to all tables being imported; it cannot be set on a per-table basis.
FILE
Default: expdat.dmp
Specifies the names of the export files to import. The default extension is .dmp. Because Export supports multiple export files (see the following description of the FILESIZE parameter), you may need to specify multiple filenames to be imported. For example:
imp scott/tiger IGNORE=y FILE = dat1.dmp, dat2.dmp, dat3.dmp FILESIZE=2048
You need not be the user who exported the export files; however, you must have read access to the files. If you were not the exporter of the export files, you must also have the IMP_FULL_DATABASE role granted to you.
FILESIZE
Default: operating-system dependent
Export supports writing to multiple export files, and Import can read from multiple export files. If, on export, you specify a value (byte limit) for the Export FILESIZE parameter, Export will write only the number of bytes you specify to each dump file. On import, you must use the Import parameter FILESIZE to tell Import the maximum dump file size you specified on export.
Note:
The maximum value that can be stored in a file is operating system-dependent. You should verify this maximum value in your Oracle operating system-specific documentation before specifying FILESIZE.
The FILESIZE value can be specified as a number followed by KB (number of kilobytes). For example, FILESIZE=2KB is the same as FILESIZE=2048. Similarly, MB specifies megabytes (1024 * 1024) and GB specifies gigabytes (1024**3). B remains the shorthand for bytes; the number is not multiplied to obtain the final file size (FILESIZE=2048B is the same as FILESIZE=2048).
For information on the maximum size of dump files, see FILESIZE.
FROMUSER
Default: none
A comma-separated list of schemas to import. This parameter is relevant only to users with the IMP_FULL_DATABASE role. The parameter enables you to import a subset of schemas from an export file containing multiple schemas (for example, a full export dump file or a multischema, user-mode export dump file).
Schema names that appear inside functional indexes, functions, procedures, triggers, type bodies, views, and so on, are not affected by FROMUSER or TOUSER processing. Only the name of the object is affected. After the import has completed, items in any TOUSER schema should be manually checked for references to old (FROMUSER) schemas, and corrected if necessary.
You will typically use FROMUSER in conjunction with the Import parameter TOUSER, which you use to specify a list of usernames whose schemas will be targets for import (see TOUSER). However, if you omit specifying TOUSER, Import will:
* Import objects into the FROMUSER schema if the export file is a full dump or a multischema, user-mode export dump file
* Create objects in the importer's schema (regardless of the presence of or absence of the FROMUSER schema on import) if the export file is a single-schema, user-mode export dump file created by an unprivileged user
Note:
Specifying FROMUSER=SYSTEM causes only schema objects belonging to user SYSTEM to be imported; it does not cause system objects to be imported.
FULL
Default: n
Specifies whether to import the entire export file.
GRANTS
Default: y
Specifies whether to import object grants.
By default, the Import utility imports any object grants that were exported. If the export was a user-mode Export, the export file contains only first-level object grants (those granted by the owner).
If the export was a full database mode Export, the export file contains all object grants, including lower-level grants (those granted by users given a privilege with the WITH GRANT OPTION). If you specify GRANTS=n, the Import utility does not import object grants. (Note that system grants are imported even if GRANTS=n.)
Note:
Export does not export grants on data dictionary views for security reasons that affect Import. If such grants were exported, access privileges would be changed and the importer would not be aware of this.
HELP
Default: none
Displays a description of the Import parameters. Enter imp HELP=y on the command line to invoke it.
IGNORE
Default: n
Specifies how object creation errors should be handled. If you accept the default, IGNORE=n, Import logs or displays object creation errors before continuing.
If you specify IGNORE=y, Import overlooks object creation errors when it attempts to create database objects, and continues without reporting the errors.
Note that only object creation errors are ignored; other errors, such as operating system, database, and SQL errors, are not ignored and may cause processing to stop.
In situations where multiple refreshes from a single export file are done with IGNORE=y, certain objects can be created multiple times (although they will have unique system-defined names). You can prevent this for certain objects (for example, constraints) by doing an import with CONSTRAINTS=n. If you do a full import with the CONSTRAINTS=n, no constraints for any tables are imported.
If a table already exists and IGNORE=y, then rows are imported into existing tables without any errors or messages being given. You might want to import data into tables that already exist in order to use new storage parameters or because you have already created the table in a cluster.
If a table already exists and IGNORE=n, then errors are reported and the table is skipped with no rows inserted. Also, objects dependent on tables, such as indexes, grants, and constraints, will not be created.
Caution:
When you import into existing tables, if no column in the table is uniquely indexed, rows could be duplicated.
INDEXES
Default: y
Specifies whether or not to import indexes. System-generated indexes such as LOB indexes, OID indexes, or unique constraint indexes are re-created by Import regardless of the setting of this parameter.
You can postpone all user-generated index creation until after Import completes, by specifying INDEXES=n.
If indexes for the target table already exist at the time of the import, Import performs index maintenance when data is inserted into the table.
INDEXFILE
Default: none
Specifies a file to receive index-creation statements.
When this parameter is specified, index-creation statements for the requested mode are extracted and written to the specified file, rather than used to create indexes in the database. No database objects are imported.
If the Import parameter CONSTRAINTS is set to y, Import also writes table constraints to the index file.
The file can then be edited (for example, to change storage parameters) and used as a SQL script to create the indexes.
To make it easier to identify the indexes defined in the file, the export file's CREATE TABLE statements and CREATE CLUSTER statements are included as comments.
Perform the following steps to use this feature:
1. Import using the INDEXFILE parameter to create a file of index-creation statements.
2. Edit the file, making certain to add a valid password to the connect strings.
3. Rerun Import, specifying INDEXES=n.
(This step imports the database objects while preventing Import from using the index definitions stored in the export file.)
4. Execute the file of index-creation statements as a SQL script to create the index.
The INDEXFILE parameter can be used only with the FULL=y, FROMUSER, TOUSER, or TABLES parameters.
LOG
Default: none
Specifies a file to receive informational and error messages. If you specify a log file, the Import utility writes all information to the log in addition to the terminal display.
PARFILE
Default: none
Specifies a filename for a file that contains a list of Import parameters. For more information on using a parameter file, see Invoking Import.
RECORDLENGTH
Default: operating system dependent
Specifies the length, in bytes, of the file record. The RECORDLENGTH parameter is necessary when you must transfer the export file to another operating system that uses a different default value.
If you do not define this parameter, it defaults to your platform-dependent value for BUFSIZ. For more information about the BUFSIZ default value, see your Oracle operating system-specific documentation.
You can set RECORDLENGTH to any value equal to or greater than your system's BUFSIZ. (The highest value is 64 KB.) Changing the RECORDLENGTH parameter affects only the size of data that accumulates before writing to the database. It does not affect the operating system file block size.
You can also use this parameter to specify the size of the Import I/O buffer.
Note:
See your Oracle operating system-specific documentation to determine the proper value or to create a file with a different record size.
RESUMABLE
Default: n
The RESUMABLE parameter is used to enable and disable resumable space allocation. Because this parameter is disabled by default, you must set RESUMABLE=y in order to use its associated parameters, RESUMABLE_NAME and RESUMABLE_TIMEOUT.
See Also:
* Oracle9i Database Concepts
* Oracle9i Database Administrator's Guide for more information about resumable space allocation
RESUMABLE_NAME
Default: 'User USERNAME (USERID), Session SESSIONID, Instance INSTANCEID'
The value for this parameter identifies the statement that is resumable. This value is a user-defined text string that is inserted in either the USER_RESUMABLE or DBA_RESUMABLE view to help you identify a specific resumable statement that has been suspended.
This parameter is ignored unless the RESUMABLE parameter is set to y to enable resumable space allocation.
RESUMABLE_TIMEOUT
Default: 7200 seconds (2 hours)
The value of the parameter specifies the time period during which an error must be fixed. If the error is not fixed within the timeout period, execution of the statement is aborted.
This parameter is ignored unless the RESUMABLE parameter is set to y to enable resumable space allocation.
ROWS
Default: y
Specifies whether or not to import the rows of table data.
SHOW
Default: n
When SHOW=y, the contents of the export file are listed to the display and not imported. The SQL statements contained in the export are displayed in the order in which Import will execute them.
The SHOW parameter can be used only with the FULL=y, FROMUSER, TOUSER, or TABLES parameter.
SKIP_UNUSABLE_INDEXES
Default: n
Specifies whether or not Import skips building indexes that were set to the Index Unusable state (by either system or user). Other indexes (not previously set Index Unusable) continue to be updated as rows are inserted.
This parameter allows you to postpone index maintenance on selected index partitions until after row data has been inserted. You then have the responsibility to rebuild the affected index partitions after the Import.
Note:
Indexes that are unique and marked Unusable are not allowed to skip index maintenance. Therefore, the SKIP_UNUSABLE_INDEXES parameter has no effect on unique indexes.
You can use the INDEXFILE parameter in conjunction with INDEXES=n to provide the SQL scripts for re-creating the index. Without this parameter, row insertions that attempt to update unusable indexes will fail.
See Also:
The ALTER SESSION statement in the Oracle9i SQL Reference
STATISTICS
Default: ALWAYS
Specifies what is done with the database optimizer statistics at import time.
The options are:
* ALWAYS
Always import database optimizer statistics regardless of whether or not they are questionable.
* NONE
Do not import or recalculate the database optimizer statistics.
* SAFE
Import database optimizer statistics only if they are not questionable. If they are questionable, recalculate the optimizer statistics.
* RECALCULATE
Do not import the database optimizer statistics. Instead, recalculate them on import.
See Also:
o Oracle9i Database Concepts for more information about the optimizer and the statistics it uses
o STATISTICS
o Importing Statistics
STREAMS_CONFIGURATION
Default: y
Specifies whether or not to import any general streams metadata that may be present in the export dump file.
See Also:
Oracle9i Streams
STREAMS_INSTANTIATION
Default: n
Specifies whether or not to import streams instantiation metadata that may be present in the export dump file. Specify y if the import is part of an instantiation in a Streams environment.
See Also:
Oracle9i Streams
TABLES
Default: none
Specifies that the Import is a table-mode import and lists the table names and partition and subpartition names to import. Table-mode import lets you import entire partitioned or nonpartitioned tables. The TABLES parameter restricts the import to the specified tables and their associated objects, as listed in Table 1-1. You can specify the following values for the TABLES parameter:
* tablename specifies the name of the table or tables to be imported. If a table in the list is partitioned and you do not specify a partition name, all its partitions and subpartitions are imported. To import all the exported tables, specify an asterisk (*) as the only table name parameter.
tablename can contain any number of '%' pattern matching characters, which can each match zero or more characters in the table names in the export file. All the tables whose names match all the specified patterns of a specific table name in the list are selected for import. A table name in the list that consists of all pattern matching characters and no partition name results in all exported tables being imported.
* partition_name and subpartition_name let you restrict the import to one or more specified partitions or subpartitions within a partitioned table.
The syntax you use to specify the preceding is in the form:
tablename:partition_name
tablename:subpartition_name
If you use tablename:partition_name, the specified table must be partitioned, and partition_name must be the name of one of its partitions or subpartitions. If the specified table is not partitioned, the partition_name is ignored and the entire table is imported.
The number of tables that can be specified at the same time is dependent on command-line limits.
As the export file is processed, each table name in the export file is compared against each table name in the list, in the order in which the table names were specified in the parameter. To avoid ambiguity and excessive processing time, specific table names should appear at the beginning of the list, and more general table names (those with patterns) should appear at the end of the list.
Although you can qualify table names with schema names (as in scott.emp) when exporting, you cannot do so when importing. In the following example, the TABLES parameter is specified incorrectly:
imp SYSTEM/password TABLES=(jones.accts, scott.emp, scott.dept)
The valid specification to import these tables is as follows:
imp SYSTEM/password FROMUSER=jones TABLES=(accts)
imp SYSTEM/password FROMUSER=scott TABLES=(emp,dept)
For a more detailed example, see Example Import of Using Pattern Matching to Import Various Tables.
Note:
Some operating systems, such as UNIX, require that you use escape characters before special characters, such as a parenthesis, so that the character is not treated as a special character. On UNIX, use a backslash (\) as the escape character, as shown in the following example:
TABLES=\(emp,dept\)
Table Name Restrictions
The following restrictions apply to table names:
* By default, table names in a database are stored as uppercase. If you have a table name in mixed-case or lowercase, and you want to preserve case-sensitivity for the table name, you must enclose the name in quotation marks. The name must exactly match the table name stored in the database.
Some operating systems require that quotation marks on the command line be preceded by an escape character. The following are examples of how case-sensitivity can be preserved in the different Import modes.
o In command-line mode:
tables='\"Emp\"'
o In interactive mode:
Table(T) to be exported: "Exp"
o In parameter file mode:
tables='"Emp"'
* Table names specified on the command line cannot include a pound (#) sign, unless the table name is enclosed in quotation marks. Similarly, in the parameter file, if a table name includes a pound (#) sign, the Import utility interprets the rest of the line as a comment, unless the table name is enclosed in quotation marks.
For example, if the parameter file contains the following line, Import interprets everything on the line after emp# as a comment and does not import the tables dept and mydata:
TABLES=(emp#, dept, mydata)
However, given the following line, the Import utility exports all three tables because emp# is enclosed in quotation marks:
TABLES=("emp#", dept, mydata)
Note:
Some operating systems require single quotation marks rather than double quotation marks, or the reverse; see your Oracle operating system-specific documentation. Different operating systems also have other restrictions on table naming.
For example, the UNIX C shell attaches a special meaning to a dollar sign ($) or pound sign (#) (or certain other special characters). You must use escape characters to get such characters in the name past the shell and into Import.
TABLESPACES
Default: none
When TRANSPORT_TABLESPACE is specified as y, use this parameter to provide a list of tablespaces to be transported into the database.
See TRANSPORT_TABLESPACE for more information.
TOID_NOVALIDATE
Default: none
When you import a table that references a type, but a type of that name already exists in the database, Import attempts to verify that the preexisting type is, in fact, the type used by the table (rather than a different type that just happens to have the same name).
To do this, Import compares the type's unique identifier (TOID) with the identifier stored in the export file. Import will not import the table rows if the TOIDs do not match.
In some situations, you may not want this validation to occur on specified types (for example, if the types were created by a cartridge installation). You can use the TOID_NOVALIDATE parameter to specify types to exclude from TOID comparison.
The syntax is as follows:
TOID_NOVALIDATE=([schemaname.]typename [, ...])
For example:
imp scott/tiger TABLE=foo TOID_NOVALIDATE=bar
imp scott/tiger TABLE=foo TOID_NOVALIDATE=(fred.type0,sally.type2,type3)
If you do not specify a schema name for the type, it defaults to the schema of the importing user. For example, in the first preceding example, the type bar defaults to scott.bar.
The output of a typical import with excluded types would contain entries similar to the following:
[...]
. importing IMP3's objects into IMP3
. . skipping TOID validation on type IMP2.TOIDTYP0
. . importing table "TOIDTAB3"
[...]
Caution:
When you inhibit validation of the type identifier, it is your responsibility to ensure that the attribute list of the imported type matches the attribute list of the existing type. If these attribute lists do not match, results are unpredictable.
TOUSER
Default: none
Specifies a list of usernames whose schemas will be targets for Import. The
IMP_FULL_DATABASE role is required to use this parameter. To import to a different schema than the one that originally contained the object, specify TOUSER. For example:
imp SYSTEM/password FROMUSER=scott TOUSER=joe TABLES=emp
If multiple schemas are specified, the schema names are paired. The following example imports scott's objects into joe's schema, and fred's objects into ted's schema:
imp SYSTEM/password FROMUSER=scott,fred TOUSER=joe,ted
If the FROMUSER list is longer than the TOUSER list, the remaining schemas will be imported into either the FROMUSER schema, or into the importer's schema, based on normal defaulting rules. You can use the following syntax to ensure that any extra objects go into the TOUSER schema:
imp SYSTEM/password FROMUSER=scott,adams TOUSER=ted,ted
Note that user ted is listed twice.
See Also:
FROMUSER for information about restrictions when using FROMUSER and TOUSER
TRANSPORT_TABLESPACE
Default: n
When specified as y, instructs Import to import transportable tablespace metadata from an export file.
TTS_OWNERS
Default: none
When TRANSPORT_TABLESPACE is specified as y, use this parameter to list the users who own the data in the transportable tablespace set.
See TRANSPORT_TABLESPACE.
USERID (username/password)
Default: none
Specifies the username/password (and optional connect string) of the user performing the import.
USERID can also be:
username/password AS SYSDBA
or
username/password@instance
or
username/password@instance AS SYSDBA
If you connect as user SYS, you must also specify AS SYSDBA in the connect string. Your operating system may require you to treat AS SYSDBA as a special string, in which case the entire string would be enclosed in quotation marks. See Invoking Import As SYSDBA for more information.
See Also:
* Oracle9i Heterogeneous Connectivity Administrator's Guide
* The user's guide for your Oracle Net protocol for information about specifying the @connect_string for Oracle Net
VOLSIZE
Specifies the maximum number of bytes in an export file on each volume of tape.
The VOLSIZE parameter has a maximum value equal to the maximum value that can be stored in 64 bits. See your Oracle operating system-specific documentation for more information.
The VOLSIZE value can be specified as number followed by KB (number of kilobytes). For example, VOLSIZE=2KB is the same as VOLSIZE=2048. Similarly, MB specifies megabytes (1024 * 1024) and GB specifies gigabytes (1024**3). The shorthand for bytes remains B; the number is not multiplied to get the final file size (VOLSIZE=2048B is the same as VOLSIZE=2048).
Import
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