Importing a Delimited-Text File
Enter the pathname of the delimited-text file (typically with a .tab, .csv, or .txt extension), or click Browse to find the file.
You might also need to confirm the character set of the file to be uploaded.
If the file is large, the next page might not appear for a few moments after you click Next.
To modify the schema of the data source later, click 
next to its name in the Folders list, and select Change Schema from the pop-up menu.