Manual:PopulateRevisionLength.php

Details
populateRevisionLength.php file is a maintenance script to populate the and  fields for old revisions created before MW 1.10.

The and  field contains the length of the article in bytes of a revision after new edit or delection.

This script runs by default when you runs. It process 200 items in a batch.

Options/Arguments
This script does not take any options or arguments.