SQL Navigator for Oracle 7.4 - User Guide

Reuses the existing datafiles making up the database. Selecting this parameter causes the Import utility to include the Reuse parameter in the datafile clause of the CREATE TABLESPACE statement. This results in the Import utility reusing the original database's datafiles after deleting their contents.

Sets the Import utility to commit after each array insert.

By default, the Import utility commits only after loading each table. If an error occurs, a rollback is performed before continuing with the next object.

Selecting this parameter prevents rollback segments from growing inordinately large and improves the performance of large imports. If the table has a uniqueness constraint it is recommended that this parameter is selected. If a table does not have a uniqueness constraint, the Import utility could produce duplicate rows if you reimport the data.

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 this parameter is not selected and a table is partitioned, each partition and subpartition in the export file are imported in a separate transaction.

For tables containing LONG, LOB, BFILE, REF, ROWID, UROWID, or DATE columns, array inserts are not done. If this parameter is selected, the Import utility commits these tables after each row.

Specifies how object creation errors should be handled. If selected, the Import utility 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 and this parameter is selected, certain objects may be created multiple times (although they will have unique system-defined names). You can prevent this for certain objects (for example, constraints) by deselecting the Constraints parameter when importing. If you do a full import with the Constraints parameter deselected, no constraints for any tables are imported.

If a table already exists and the Ignore errors parameter is selected, then rows are imported into existing tables without any errors or messages being given. This may be helpful when importing 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 this parameter is not selected, the Import utility logs or displays object creation errors before continuing. If a table already exists, then errors are reported and the table is skipped with no rows inserted. Objects dependent on tables, such as indexes, grants, and constraints, will not be created.

When this parameter is selected the contents of the export file are displayed and not imported. The SQL statements contained in the export are displayed in the order in which the Import utility will execute them.

The size of the buffer, in bytes, through which the data rows are transferred.

BUFFER determines the number of rows in the array inserted by the Import utility. 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, the Import utility attempts to allocate a larger buffer.

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.