simple utility commands (src/backend/commands)

<div class="Section1"><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Folks,</span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">I would like to understand how the ‘simple’ backend commands work. </span></font><p
class="MsoNormal"><fontface="Arial" size="2"><span style="font-size:10.0pt; 
font-family:Arial">After reading the “</span></font>How PostgreSQL Processes a Query”, I was wondering <p
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12.0pt">Which command would be the easiest to begin with? (For a newbie of course.)</span></font><p
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12.0pt"> </span></font><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="font-size:
12.0pt">Regards,</span></font><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="font-size:
12.0pt">Gevik.</span></font><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="font-size:
12.0pt"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font></div>