|修改时间 23-MAY-2011 类型 HOWTO 状态 PUBLISHED|
Checked for relevance on 10-25-2010
With the old Import utility there is the option of using the parameters "buffer" and "commit=y".
That way, there are lower chances of running into issues with the Undo tablespace. Is there anything similar in Import DataPump or it's necessary to increase the Undo tablespace?
An example experiencing issues is when using DataPump to re-organize tables.
Unlike the traditional Export and Import utilities, which used the BUFFER, COMMIT, COMPRESS, CONSISTENT, DIRECT and RECORDLENGTH parameters, DataPump needs no tuning to achieve maximum performance.
DataPump "chooses" the best method to ensure that data and metadata are exported and imported in the most efficient manner. Initialization parameters should be sufficient upon installation.
However, you can get
ORA-30036: unable to extend segment by 8 in undo tablespace 'UNDOTBS1'
during the Import (impdp) if indexes are present in some cases.
Impdp maintains indexes during import by default and does not use direct_path if tables and indexes
are already created. However, if there is no index to enforce constraints and you specify
with the DataPump Import command line, DataPump can use direct path method to do the import.
To get around potential issues with the UNDO tablespace in this case:
- load data by direct path by disabling primary key constraint (using ALTER TABLE ... MODIFY CONSTRAINT ... DISABLE NOVALIDATE) and using access_method=direct_path.
-after loading data, enable primary key constraint (using ALTER TABLE ... MODIFY CONSTRAINT ... ENABLE VALIDATE)
NOTE:413965.1 - Oracle DataPump Quick Start
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