SQL*Loader loads data from external files into tables of an Oracle database. It has a powerful data parsing engine that puts little limitation on the format of the data in the data file. You can use SQL*Loader to do the following:
Load data across a network if your data files are on a different system than the database.
Load data from multiple data files during the same load session.
Load data into multiple tables during the same load session.
Specify the character set of the data.
Selectively load data (you can load records based on the records' values).
Manipulate the data before loading it, using SQL functions.
Generate unique sequential key values in specified columns.
Use the operating system's file system to access the data files.
Load data from disk, tape, or named pipe.
Generate sophisticated error reports, which greatly aid troubleshooting.
Load arbitrarily complex object-relational data.
Use secondary data files for loading LOBs and collections.
Use conventional, direct path, or external table loads. See "Conventional Path Loads_ Direct Path Loads_ and External Table Loads".
You can use SQL*Loader in two ways: with or without a control file. A control file controls the behavior of SQL*Loader and one or more data files used in the load. Using a control file gives you more control over the load operation, which might be desirable for more complicated load situations. But for simple loads, you can use SQL*Loader without specifying a control file; this is referred to as SQL*Loader express mode. See SQL*Loader Express .
The output of SQL*Loader is an Oracle database (where the data is loaded), a log file, a bad file if there are rejected records, and potentially, a discard file.
Figure 7-1 shows an example of the flow of a typical SQL*Loader session that uses a control file.
Figure 7-1 SQL*Loader Overview