\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{kaiman}
\pdfinfo{
  /Title (compsci-exam.pdf)
  /Creator (Cheatography)
  /Author (kaiman)
  /Subject (compsci exam Cheat Sheet)
}

% Lengths and widths
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\addtolength{\textheight}{-1cm}
\addtolength{\hoffset}{-3cm}
\addtolength{\voffset}{-2cm}
\setlength{\tabcolsep}{0.2cm} % Space between columns
\setlength{\headsep}{-12pt} % Reduce space between header and content
\setlength{\headheight}{85pt} % If less, LaTeX automatically increases it
\renewcommand{\footrulewidth}{0pt} % Remove footer line
\renewcommand{\headrulewidth}{0pt} % Remove header line
\renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit
% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
\newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns
\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
\definecolor{HeadBackground}{HTML}{333333}
\definecolor{FootBackground}{HTML}{666666}
\definecolor{TextColor}{HTML}{333333}
\definecolor{DarkBackground}{HTML}{8D87D4}
\definecolor{LightBackground}{HTML}{F0F0F9}
\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{compsci exam Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{kaiman} via \textcolor{DarkBackground}{\uline{cheatography.com/208299/cs/44584/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}kaiman \\
  \uline{cheatography.com/kaiman} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 10th October, 2024.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{4}

\begin{tabularx}{3.833cm}{p{0.58361 cm} x{2.84939 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{Docker FIle}}  \tn
% Row 0
\SetRowColor{LightBackground}
{\bf{FROM}} & Create a new build stage from a base image. \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
{\bf{RUN}} & Execute build commands. \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
{\bf{COPY}} & Copy files and directories. \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
{\bf{COPY}} & Specify default commands. \tn 
% Row Count 8 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{1.09856 cm} x{2.33444 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{MySQL}}  \tn
% Row 0
\SetRowColor{LightBackground}
{\bf{SELECT}} & Extracts data from database \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
{\bf{UPDATE}} & Updates data in a database \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
{\bf{DELETE}} & deletes data from a database \tn 
% Row Count 4 (+ 2)
% Row 3
\SetRowColor{white}
{\bf{INSERT INTO}} & inserts new data into a database \tn 
% Row Count 6 (+ 2)
% Row 4
\SetRowColor{LightBackground}
{\bf{CREATE DATABASE}} & Creates a new database \tn 
% Row Count 8 (+ 2)
% Row 5
\SetRowColor{white}
{\bf{ALTER DATABASE}} & Modifies a database \tn 
% Row Count 10 (+ 2)
% Row 6
\SetRowColor{LightBackground}
{\bf{CREATE TABLE}} & Creates a new Table \tn 
% Row Count 12 (+ 2)
% Row 7
\SetRowColor{white}
{\emph{*DROP TABLE}} & Deletes a table \tn 
% Row Count 14 (+ 2)
% Row 8
\SetRowColor{LightBackground}
{\bf{CREATE INDEX}} & Creates a search key \tn 
% Row Count 16 (+ 2)
% Row 9
\SetRowColor{white}
{\bf{DROP INDEX}} & Deletes search key \tn 
% Row Count 18 (+ 2)
% Row 10
\SetRowColor{LightBackground}
ORDER BY & List by a certain column, DESC or ASC, etc. \tn 
% Row Count 20 (+ 2)
% Row 11
\SetRowColor{white}
DISTINCT & Filter only unique inputs \tn 
% Row Count 21 (+ 1)
% Row 12
\SetRowColor{LightBackground}
WHERE & Filter function (SELECT * FROM Customers WHERE Country='Mexico') \tn 
% Row Count 24 (+ 3)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{p{0.54928 cm} x{2.88372 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{HTTP}}  \tn
% Row 0
\SetRowColor{LightBackground}
GET & Fetch the resource from web \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
PUT & Update the resource \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
POST & Create a resource to send to web \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
\seqsplit{DELETE} & Delete resource from web \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{0.99557 cm} x{2.43743 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{Memory Resources}}  \tn
% Row 0
\SetRowColor{LightBackground}
Caching Heiarchy & CPU Registers, L1, L2, L3, RAM, SSD/HDD, Cloud \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
FIFO & First In First Out, Evict Oldest Entry \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
LRU & Least Recently Used, Evict the entry that has been used longest ago. Move hits to front \tn 
% Row Count 8 (+ 4)
% Row 3
\SetRowColor{white}
\seqsplit{Transposing} & Column by Column, faster than row by row for long arrays. \tn 
% Row Count 11 (+ 3)
% Row 4
\SetRowColor{LightBackground}
FS(File System) & Caches data in the RAM. Uses memory and avoids storage reads. \tn 
% Row Count 14 (+ 3)
% Row 5
\SetRowColor{white}
Stale Data & Old files are deleted from the cache. SSD is large, so freshness more important than space there. \tn 
% Row Count 18 (+ 4)
% Row 6
\SetRowColor{LightBackground}
PyArrow & Cache Friendly table layout. Saves time when handling large datasets by turning each value into Pyarrow Types. \tn 
% Row Count 22 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{3.833cm}{x{0.99557 cm} x{2.43743 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{3.833cm}}{\bf\textcolor{white}{Compute Resources}}  \tn
% Row 0
\SetRowColor{LightBackground}
Locks & Making a code execute on only one thread. Avoids discrepancies from other threads changing vals. \tn 
% Row Count 4 (+ 4)
% Row 1
\SetRowColor{white}
\seqsplit{Threading.lock()} & class threading.Lock The class implementing primitive lock objects. Once a thread has acquired a lock, subsequent attempts to acquire it block, until it is released; any thread may release it.  Changed in version 3.13: Lock is now a class. In earlier Pythons, Lock was a factory function which returned an instance of the underlying private lock type. \tn 
% Row Count 17 (+ 13)
% Row 2
\SetRowColor{LightBackground}
\seqsplit{lock.acquire()} & Acquire a lock, blocking or non-blocking. Locks code under lock to one thread. \tn 
% Row Count 20 (+ 3)
% Row 3
\SetRowColor{white}
\seqsplit{lock.release()} & Release a lock. This can be called from any thread, not only the thread which has acquired the lock. \tn 
% Row Count 24 (+ 4)
% Row 4
\SetRowColor{LightBackground}
GIL & Global Interpreter Lock. \tn 
% Row Count 25 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}