The terminal window or console provides current processing feedback so that the user can view the status at any specified time. During the load process, the system displays key milestones including—input file parsing, a count of inserts and updates found, and progress checkpoints as data is loaded.

The command line prompt is set by default (through the configuration file) to report on items processed and errors every two minutes. The configuration file changes can set it to a different time interval and/or to a count of items interval. The notification information can also be directed to email (among other output types).

In addition, an output file with the DataLoaderResults.log.txt default name logs progress so that you can keep track of the complete process. In case of a major failure (power loss or network connection), the log file provides information about how much has already been processed. It logs results for each operation attempted in the process.

Data Loader never deletes or truncates this log file. It'll always append to the existing file.

You're advised to delete this file when its contents are no longer useful.