simple SQL question

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font-family:Arial">Hello All:</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
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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 your input on how I should approach a problem.</span></font><p class="MsoNormal"><font
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font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Say I have a table of companies and one attribute is the market capitalization of these
companies.</span></font><pclass="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt; 
font-family:Arial">I have another table (definition below) and it contains capitalization levels. </span></font><p
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font-family:Arial">For example Micro Cap, Mid Cap, and Large Cap.    However, the table </span></font><p
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font-family:Arial">CAPITALIZATIONLEVEL, only contains the upper cutoff of the levels.</span></font><p
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font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">The question is: What is the most efficient way to assign/join the capitalization levels to the
companies?</span></font><pclass="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 could create a function that given a market cap in millions would return the matching cap
level,</span></font><pclass="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt; 
font-family:Arial">by using a cursor to step through CAPITALIZATIONLEVEL  from lowest to highest. </span></font><p
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font-family:Arial">This function would be declared STABLE.</span></font><p class="MsoNormal"><font face="Arial"
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font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">-or maybe-</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
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font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">a function that RETURNS SETOF and the rows in the set returned would contain both the lower and
</span></font><pclass="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt; 
font-family:Arial">upper limits of the cap level.  The lower limit would be calc’ed  by using a cursor to step through
</span></font><pclass="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt; 
font-family:Arial">CAPITALIZATIONLEVEL  from lowest to highest.  This function would be declared
STABLE.</span></font><pclass="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"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Which method would execute more efficiently?  </span></font><p class="MsoNormal"><font face="Arial"
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font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Thanks for considering my issue.</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">KevinDuffy</span></font><p class="MsoNormal"><font face="Times New Roman"
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12.0pt"> </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="Times New Roman" size="3"><span style="font-size:
12.0pt"> </span></font><p class="MsoNormal"><font face="Arial" size="3"><span style="font-size:12.0pt;
font-family:Arial">CREATE TABLE capitalizationlevel</span></font><p class="MsoNormal"><font face="Arial" size="3"><span
style="font-size:12.0pt;
font-family:Arial">(</span></font><p class="MsoNormal"><font face="Arial" size="3"><span style="font-size:12.0pt;
font-family:Arial">  capitallevelkey serial NOT NULL,</span></font><p class="MsoNormal"><font face="Arial"
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font-family:Arial">  caplevelname character(10) NOT NULL,</span></font><p class="MsoNormal"><font face="Arial"
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font-family:Arial">  caplevelmillions integer NOT NULL,     </span></font><font face="Wingdings"><span
style="font-family:Wingdings">ß</span></font><fontface="Arial"><span style="font-family:Arial"> this is the upper
limit</span></font><pclass="MsoNormal"><font face="Arial" size="3"><span style="font-size:12.0pt; 
font-family:Arial">  CONSTRAINT pk_capitalizationlevel PRIMARY KEY (capitallevelkey)</span></font><p
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font-family:Arial">)</span></font><p class="MsoNormal"><font face="Arial" size="3"><span style="font-size:12.0pt;
font-family:Arial">WITH (OIDS=FALSE);</span></font><p class="MsoNormal"><font face="Arial" size="3"><span
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font-family:Arial">ALTER TABLE capitalizationlevel OWNER TO postgres;</span></font></div>