\documentclass[a4paper]{article}

\usepackage{pgfplots}

\begin{document}

\begin{tikzpicture}
	\begin{axis}[compat=1.3]
	\addplot table {
	A B
	0 0
	1 1

	1 2
	2 2
	};
	\end{axis}
\end{tikzpicture}

\begin{tikzpicture}
	\begin{axis}[compat=1.4]
	\addplot table {
	A B
	0 0
	1 1

	1 2
	2 2
	};
	\end{axis}
\end{tikzpicture}
\end{document}

