public function execute() {
		$this->output( "Creating username spoofs...\n" );

		$userCol = $this->getUserColumn();
		$iterator = new BatchRowIterator( $this->getDB( DB_MASTER ),
			$this->getTableName(),
			$this->getPrimaryKey(),
			$this->getBatchSize()
		);
		$iterator->setFetchColumns( [ $userCol ] );

		$n = 0;
		foreach ( $iterator as $batch ) {
			$items = [];
			foreach ( $batch as $row ) {
				$items[] = $this->makeSpoofUser( $row->$userCol );
			}

			$n += count( $items );
			$this->output( "...$n\n" );
			$this->batchRecord( $items );
			$this->waitForSlaves();
		}

		$this->output( "$n user(s) done.\n" );
	}