\input{figure/tikz/data}

\begin{tikzpicture}
\node[database,label=left:$D_{\text{test}}$] (test) at (0,-1){};

\node[rectangle,draw] (pred1) at (2,0) {Predictor 1};
\node[rectangle,draw] (pred2) at (2,-1) {Predictor 2};
\node[rectangle,draw] (pred3) at (2,-2) {Predictor 3};


\node[database,label=right:$P_{1}$] (p1) at (4,0){};
\node[database,label=right:$P_{2}$] (p2) at (4,-1){};
\node[database,label=right:$P_{3}$] (p3) at (4,-2){};

\draw[->] (test) to (pred1);
\draw[->] (test) to (pred2);
\draw[->] (test) to (pred3);

\draw[->] (pred1) to (p1);
\draw[->] (pred2) to (p2);
\draw[->] (pred3) to (p3);

\end{tikzpicture}