You are using flat files as the data source for one of your data warehousing applications. To
optimize the application performance, you plan to move the data from the flat files to
clustered tables in an Oracle database. While migrating the data, you want to have minimal
impact on the database performance and optimize the data load operation. Which method
would you use to load data into the Oracle database?
A.
Use the external table population.
B.
Use the Oracle Data Pump export and import utility.
C.
Use the conventional path data load of the SQL*Loader utility.
D.
Use the INSERT INTO…SELECT command to load the data.
C
When to Use a Conventional Path Load
If load speed is most important to you, you should use direct path load because it is faster than conventional path load. However, certain restrictions on direct path loads may require you to use a conventional path load. You should use a conventional path load in the following situations:
When accessing an indexed table concurrently with the load, or when applying inserts or updates to a nonindexed table concurrently with the load
To use a direct path load (with the exception of parallel loads), SQL*Loader must have exclusive write access to the table and exclusive read/write access to any indexes.
*When loading data into a clustered table
A direct path load does not support loading of clustered tables.
When loading a relatively small number of rows into a large indexed table
During a direct path load, the existing index is copied when it is merged with the new index keys. If the existing index is very large and the number of new keys is very small, then the index copy time can offset the time saved by a direct path load.
When loading a relatively small number of rows into a large table with referential and column-check integrity constraints