The data can be loaded from any text file and inserted in to the database. There are several types of files within the process of the SQL loader. There are three types of important files which are used prior to the process of SQL loader and those files are:
- The DATA file
- The CONTROL file
- The parameter file
- The LOG file
- The DISCARD file
- The BAD file
The Control File
The SQL Loader Control file contains information that describes how the data will be loaded. It contains the
- Table name
- Column Data types
- Field Delimiters etc.
Manually creating a control file is an error prone process although when purchasing oracle,
(i assume) the control file comes with it along with the sql loader utility.
(That is why they call it ORACLE`s SQL loader utility.No point of creating a control file if you paid money to ORACLE).
The control file can also specify that records are in a a fixed format. (A file is in fixed format when all records in a DATA file are of the same length).
Below is an image of the SQL loader Architecture