Once the data has been loaded, you can reenable the constraints.
If none of those options gives you adequate performance, you should investigate the options
Oracle has introduced for data migration tuning. Those options include the following:
The append hint for insert commands Like the Direct Path Loader, the APPEND hint
loads blocks of data into a table, starting at the high water mark for the table. Use of the
APPEND hint may increase your space usage.
The nologging option If you are performing a create table as select command, use the
nologging option to avoid writing to the redo logs during the operation.
The parallel option Parallel Query uses multiple processes to accomplish a single task.
For a create table as select, you can parallelize both the create table portion and the query.
If you use the parallel option, you should also use the nologging option; otherwise, the
parallel operations will have to wait due to serialized writes to the online redo log files.
Before using any of these advanced options, you should first investigate the target table??™s
structures to make sure you??™ve avoided the common traps cited earlier in this section.
You can also use programming logic to force inserts to be processed in arrays rather than
as an entire set. For example, COBOL and C support array inserts, thus reducing the size of the
transactions required to process a large set of data.
Bulk Deletes: The truncate Command
Occasionally, users attempt to delete all the rows from a table at once.
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