The following scenario creates and loads a data warehouse
table with external data.
To load a table initially
Create the table as type RAW to
take advantage of light appends and to avoid the overhead of logging
during the load.
CREATE RAW TABLE tab1 ...
Describe the external data file to the database server
with the CREATE EXTERNAL TABLE statement,
specifying the EXPRESS statement in the USING clause.
Load the table.
INSERT INTO tab1 SELECT * FROM ext_tab
The
table loads quickly, and the operation uses very little log space.
Verify the integrity of the data.
Create indexes on the table so that queries run more quickly.
Perform a level-0 backup so that you can restore the table
later, if necessary. You do not need to perform this level-0 backup
if it would be just as easy to reload the table from the original
source in the case of a problem.