[Tex/LaTex] Resize an eqnarray environment

Question

I am writing a mathematical model using eqnarray environment in beamer, the problem is that I need it to be smaller, so I tried to use resize it using \scalebox or resizebox but I got error (not familiar with them thoug). Is there an easy way to resize the eqnarray environment ? (Do not want to use the \small, \tiny to change font size). Below there is a little equation I would like to apply some resize action. Thanks in advance.

\documentclass[hyperref={pdfpagelabels=false}]{beamer}
\usepackage{amssymb,amsmath}

\begin{document}
\begin{frame}{test}
\begin{eqnarray}    
&& \textbf{TP} ~~\text{Max} \sum_{i \in N\setminus\{4\}} J_{i} z_{i} 
\label{S1}\\
&& \text{st} \nonumber\\
&& \sum_{j \in N} xv_{ij} = z_{i}, ~~\forall i \in N \label{S2}
\end{frame}
\end{document}

Answer 1

with use of mathtools and nccmath you can slightly reduce size of equation (without changing font size):

\documentclass[hyperref={pdfpagelabels=false}]{beamer}
\usepackage{mathtools, % instead amsmath, provide `\mathclap`
            nccmath,   % for smaller `sum` symbol
            amssymb}

\begin{document}
\begin{frame}{test}
    \begin{align}
& \textbf{TP} ~~\max \medop\sum_{\mathclap{i \in N\setminus\{4\}}} J_{i} z_{i}
\label{S1}\\
& \text{st } 
  \medop\sum_{j \in N} xv_{ij} = z_{i},\ \forall i \in N \label{S2}
    \end{align}
\end{frame}
\end{document}

note: eqnarray is long time deprecated and replaced with math environment from amsmath.

for comparison result with your mwe: