From the runBatchedQuery.php maintenance script:

		do {
			$this->output( "Batch $n: " );
			$n++;
			$dbw->query( $query, __METHOD__ );
			$affected = $dbw->affectedRows();
			$this->output( "$affected rows\n" );
			wfWaitForSlaves();
		} while ( $affected > 0 );

This should be easily enough modified to do it...

gerritadmin wrote:

Change 158310 had a related patch set uploaded by Reedy:
Don't update the entire table in one query

https://gerrit.wikimedia.org/r/158310

gerritadmin wrote:

Change 158310 merged by jenkins-bot:
Don't update the entire table in one query to avoid melting servers

https://gerrit.wikimedia.org/r/158310