About this task
The following scenario creates and loads a data warehouse
table with external data.
To load a table initially
Procedure
- 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.