[Tex/LaTex] Showing the overview of section in beamer

Question

I am making a presentation in beamer, and I want to display overview of the whole document at the beginning and overview of upcoming section. But I have too many sections and subsections, so the default table of contents gets too much crowded. I want to do either of two things:

1) Have the main table of contents that contains only section titles. (I know, I can use \setbeamertemplate{subsection in toc}{\ }. But it gives unnatural spacing). Also, have an expanded version of table of contents that expands only the current section into subsections. Note that I can gray-out the other subsections, but they still take up space, I don't want to do that.

OR

2) Have the main table of content same as above. Also, a slide that contains only the section title expanded into subsections (without mention of other sections).

Also, I want these things to be automated, and I don't want to add a frame manually by myself when I start a new section, because there are so many sections and I may forget.

Answer 1

If you opt for option 1. (showing only section titles), you could use hideallsubsections option which shows only sections. Maybe it will fix your spacing problem (you should have given a MWE to allow testing).

\begin{frame}
\frametitle{Table of Contents}
\tableofcontents[hideallsubsections]
\end{frame}

This option fits well with a presentation at every new section of its detailed contents. Here is a code for that (to put just after \begin{document} which use hideothersubections:

\AtBeginSection[]{
  \begin{frame}{Outline}
  \small \tableofcontents[currentsection, hideothersubsections]
  \end{frame} 
}

If you opt for option 2. (having a big table of contents on several slides), you could decide to put only one section per slide:

\tableofcontents[sections={1}]

You could also be interested in showing the whole table of contents on two columns. Here is an example:

\begin{frame}{Plan}
  \begin{columns}[t]
  \begin{column}{5cm}
  \tableofcontents[sections={1-4},currentsection, hideothersubsections]
  \end{column}
  \begin{column}{5cm}
  \tableofcontents[sections={5-8},currentsection,hideothersubsections]
  \end{column}
  \end{columns}
\end{frame}

And there is the allowframebreaks option to display a classic talbe of contents on several slides:

\begin{frame}[allowframebreaks]
  \tableofcontents
\end{frame}