Export Options

There are four data export modes:
• Full
• User
• Table
• Tablespace

The options are:

• buffer – Specifies the size, in bytes, of the buffer used to fetch the rows. If 0 is specified, only one row is fetched at a time. This parameter only applies to conventional (non direct) exports.

• compress – When “Y”, export will mark the table to be loaded as one extent for the import utility. If “N”, the current storage options defined for the table will be used. Although this option is only implemented on import, it can only be specified on export.

• consistent – [N] Specifies the set transaction read only statement for export, ensuring data consistency. This option should be set to “Y” if activity is anticipated while the exp command is executing.
If ‘Y’ is set, confirm that there is sufficient undo segment space to avoid the export session getting the ORA-1555 Snapshot too old error.

• constraints – [Y] Specifies whether table constraints should be exported with table data.

• direct – [N] Determines whether to use direct or conventional path export. Direct path exports bypass the SQL command, thereby enhancing performance.

• feedback – [0] Determines how often feedback is displayed. A value of feedback=n displays a dot for every n rows processed. The display shows all tables exported not individual ones. From the output below, each of the 20 dots represent 50,000 rows, totaling 1 million rows for the table.

About to export specified tables via Direct Path ... . . exporting table TABLE_WITH_ONE_MILLION_ROWS .................... 1000000 rows exported

s • file – The name of the export file. Multiple files can be listed, separated by commas. When export fills the filesize, it will begin writing to the next file in the list.

• filesize – The maximum file size, specified in bytes.

• flashback_scn – The system change number (SCN) that export uses to enable flashback.

• flashback_time – Export will discover the SCN that is closest to the specified time. This SCN is used to enable flashback.

• full – The entire database is exported.

• grants – [Y] Specifies object grants to export.

• help – Shows command line options for export.

• indexes – [Y] Determines whether index definitions are exported. The index data is never exported.

• log – The filename used by export to write messages. The same messages that appear on the screen are written to this file:

• object_consistent – [N] Specifies whether export uses SET TRANSACTION READ ONLY to ensure that the data being exported is consistent.

• owner – Only the owner’s objects will be exported.

• parfile – The name of the file that contains the export parameter options. This file can be used instead of specifying all the options on the command line for each export.

• query – Allows a subset of rows from a table to be exported, based on a SQL where clause (discussed later in this chapter).

• recordlength – Specifies the length of the file record in bytes. This parameter affects the amount of data that accumulates before it is written to disk. If not specified, this parameter defaults to the value specific to that platform. The highest value is 64KB.

• resumable – [N] Enables and disables resumable space allocation. When “Y”, the parameters resumable_name and resumable_timeout are utilized.

• resumable_name – User defined string that helps identify a resumable statement that has been suspended. This parameter is ignored unless resumable = Y.

• resumable_timeout – [7200 seconds] The time period in which an export error must be fixed. This parameter is ignored unless resumable = Y.

• rows – [Y] Indicates whether or not the table rows should be exported.

• statistics – [ESTIMATE] Indicates the level of statistics generated when the data is imported. Other options include COMPUTE and NONE.

• tables – Indicates that the type of export is table-mode and lists the tables to be exported. Table partitions and sub partitions can also be specified.

• tablespaces – Indicates that the type of export is tablespace-mode, in which all tables assigned to the listed tablespaces will be exported. This option requires the EXP_FULL_DATABASE role.

• transport_tablespace – [N] Enables the export of metadata needed for transportable tablespaces.

• triggers – [Y] Indicates whether triggers defined on export tables will also be exported.

• tts_full_check – [FALSE] When TRUE, export will verify that when creating a transportable tablespace, a consistent set of objects is exported.

• userid – Specifies the userid/password of the user performing the export.

• volsize – Specifies the maximum number of bytes in an export file on each tape volume. The functionality of the export utility has been significantly enhanced in recent versions of Oracle. To check which options are available in any release use:

exp help=y






Import Options

The import modes are the same as the export modes (Full, User, Table, Tablespace). Imports support the following options:

• buffer – Specifies the size, in bytes, of the buffer used to insert the data.

• commit– [N] Specifies whether import should commit after each array insert. By default, import commits after each table is loaded, however, this can be quite taxing on the rollback segments or undo space for extremely large tables.

• compile– [Y] Tells import to compile procedural objects as they are imported.

• constraints – [Y] Specifies whether table constraints should also be imported with table data.

• datafiles – Used only with transport_tablespace. This parameter lists datafiles to be transported to the database.

• destroy – [N] Determines if existing datafiles should be reused. A value of Y will cause import to include the reuse option in the datafile clause of the create tablespace statement.

• feedback – [0] Determines how often feedback is displayed. A value of feedback=10 displays a dot for every 10 rows processed. This option applies to the total tables imported, not individual ones.
Another way to measure the number of rows that have been processed is to execute the following query while the import is active:

select rows_processed
from v$sqlarea
where sql_text like 'INSERT %INTO "%'
and command_type = 2
and open_versions > 0;

• file – The name of the export file to import. Multiple files can be listed, separated by commas. When export reaches the filesize it will begin writing to the next file in the list.

• filesize – The maximum file size, specified in bytes.

• fromuser – A comma delimited list of schemas from which to import. If the export file contains many users or even the entire database, the fromuser option enables only a subset of those objects (and data) to be imported.

• full – The entire export file is imported.

• grants - [Y] Specifies to import object grants.

• help – Shows command line options for import.

• ignore – [N] Specifies how object creation errors should be handled. If a table already exists and ignore=y, then the rows are imported to the existing tables, otherwise errors will be reported and no rows are loaded into the table.

• indexes – [Y] Determines whether indexes are imported.

• indexfile – Specifies a filename that contains index creation statements. This file can be used to build the indexes after the import has completed.

• log – The filename used by import to write messages.

• parfile – The name of the file that contains the import parameter options. This file can be used instead of specifying all the options on the command line.

• recordlength – Specifies the length of the file record in bytes. This parameter is only used when transferring export files between operating systems that use different default values.

• resumable – [N] Enables and disables resumable space allocation. When “Y”, the parameters resumable_name and resumable_timeout are utilized.

• resumable_name – User defined string that helps identify a resumable statement that has been suspended. This parameter is ignored unless resumable = Y.

• resumable_timeout – [7200 seconds] The time period in which an error must be fixed. This parameter is ignored unless resumable=Y.

• rows – [Y] Indicates whether or not the table rows should be imported.

• show – [N] When show=y, the DDL within the export file is displayed.

• skip_unusable_indexes – [N] Determines whether import skips the building of indexes that are in an unusable state.

• statistics – [ALWAYS] Determines the level of optimizer statistics that are generated on import. The options include ALWAYS, NONE, SAFE and RECALCULATE.
ALWAYS imports statistics regardless of their validity. NONE does not import or recalculate any optimizer statistics. SAFE will import the statistics if they appear to be valid, otherwise they will be recomputed after import. RECALCULATE always generates new statistics after import.

• streams_configuration – [Y] Determines whether or not any streams metadata present in the export file will be imported.

• streams_instantiation – [N] Specifies whether or not to import streams instantiation metadata present in the export file.

• tables – Indicates that the type of export is table-mode and lists the tables to be exported. Table partitions and sub partitions can also be specified.

• tablespaces – When transport_tablespace=y, this parameter provides a list of tablespaces.

• toid_novalidate – Specifies whether or not type validation should occur on import. Import compares the type’s unique ID (TOID) with the ID stored in the export file. No table rows will be imported if the TOIDs do not match.
This parameter can be used to specify types to exclude from TOID comparison.

• to_user – Specifies a list of user schemas that will be targets for imports.

• transport_tablespace – [N] When Y, transportable tablespace metadata will be imported from the export file.

• tts_owners – When transport_tablespace=Y, this parameter lists the users who own the data in the transportable tablespace set.

• userid – Specifies the userid/password of the user performing the import.

• volsize – Specifies the maximum number of bytes in an export file on each tape volume. To check which options are available in any release of import use:

imp help=y



The above is an excerpt from Oracle Utilities - Using Hidden Programs, Import/Export, SQL Loader, oradebug, Dbverify, Tkprof and More by Rampant TechPress (Dave Moore).