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Lu, Huayi e6fa411af0 DWS DEV 830.201 version 
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com>
Co-authored-by: Lu, Huayi <luhuayi@huawei.com>
Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
2024-05-16 07:24:04 +00:00

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<a name="EN-US_TOPIC_0000001188270554"></a><a name="EN-US_TOPIC_0000001188270554"></a>
<h1 class="topictitle1">Searching a Table</h1>
<div id="body8662426"><p id="EN-US_TOPIC_0000001188270554__p142552022163610">This section describes how to use text search operators to search for database tables.</p>
<ul id="EN-US_TOPIC_0000001188270554__u32c38f23b9094a2ea2bc2bd147709db3"><li id="EN-US_TOPIC_0000001188270554__l3d92deacf1d54f4c8f600ae7bf7052a8">A simple query to print each row that contains the word <strong id="EN-US_TOPIC_0000001188270554__b842352706151058">science</strong> in its <strong id="EN-US_TOPIC_0000001188270554__b842352706163949">body</strong> column is as follows:<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001188270554__sc5d97879cd474dea9ba08a6ed157c429"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span>
<span class="normal">15</span>
<span class="normal">16</span>
<span class="normal">17</span>
<span class="normal">18</span>
<span class="normal">19</span>
<span class="normal">20</span>
<span class="normal">21</span>
<span class="normal">22</span>
<span class="normal">23</span>
<span class="normal">24</span>
<span class="normal">25</span>
<span class="normal">26</span>
<span class="normal">27</span>
<span class="normal">28</span>
<span class="normal">29</span>
<span class="normal">30</span>
<span class="normal">31</span>
<span class="normal">32</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">DROP</span><span class="w"> </span><span class="k">SCHEMA</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="n">tsearch</span><span class="w"> </span><span class="k">CASCADE</span><span class="p">;</span>
<span class="k">CREATE</span><span class="w"> </span><span class="k">SCHEMA</span><span class="w"> </span><span class="n">tsearch</span><span class="p">;</span>
<span class="k">CREATE</span><span class="w"> </span><span class="k">TABLE</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="p">(</span><span class="n">id</span><span class="w"> </span><span class="nb">int</span><span class="p">,</span><span class="w"> </span><span class="n">body</span><span class="w"> </span><span class="nb">text</span><span class="p">,</span><span class="w"> </span><span class="n">title</span><span class="w"> </span><span class="nb">text</span><span class="p">,</span><span class="w"> </span><span class="n">last_mod_date</span><span class="w"> </span><span class="nb">date</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="s1">'Philology is the study of words, especially the history and development of the words in a particular language or group of languages.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Philology'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="s1">'Mathematics is the science that deals with the logic of shape, quantity and arrangement.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Mathematics'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">3</span><span class="p">,</span><span class="w"> </span><span class="s1">'Computer science is the study of processes that interact with data and that can be represented as data in the form of programs.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Computer science'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">4</span><span class="p">,</span><span class="w"> </span><span class="s1">'Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Chemistry'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">5</span><span class="p">,</span><span class="w"> </span><span class="s1">'Geography is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and planets.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Geography'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">6</span><span class="p">,</span><span class="w"> </span><span class="s1">'History is a subject studied in schools, colleges, and universities that deals with events that have happened in the past.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'History'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">7</span><span class="p">,</span><span class="w"> </span><span class="s1">'Medical science is the science of dealing with the maintenance of health and the prevention and treatment of disease.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Medical science'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">INSERT</span><span class="w"> </span><span class="k">INTO</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">VALUES</span><span class="p">(</span><span class="mi">8</span><span class="p">,</span><span class="w"> </span><span class="s1">'Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.'</span><span class="p">,</span><span class="w"> </span><span class="s1">'Physics'</span><span class="p">,</span><span class="w"> </span><span class="s1">'2010-1-1'</span><span class="p">);</span>
<span class="k">SELECT</span><span class="w"> </span><span class="n">id</span><span class="p">,</span><span class="w"> </span><span class="n">body</span><span class="p">,</span><span class="w"> </span><span class="n">title</span><span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">to_tsvector</span><span class="p">(</span><span class="s1">'english'</span><span class="p">,</span><span class="w"> </span><span class="n">body</span><span class="p">)</span><span class="w"> </span><span class="o">@@</span><span class="w"> </span><span class="n">to_tsquery</span><span class="p">(</span><span class="s1">'english'</span><span class="p">,</span><span class="w"> </span><span class="s1">'science'</span><span class="p">);</span>
<span class="w"> </span><span class="n">id</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">body</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">title</span><span class="w"> </span>
<span class="c1">----+-------------------------------------------------------------------------------------------------------------------------+---------</span>
<span class="w"> </span>
<span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Mathematics</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="n">that</span><span class="w"> </span><span class="n">deals</span><span class="w"> </span><span class="k">with</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">logic</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">shape</span><span class="p">,</span><span class="w"> </span><span class="n">quantity</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">arrangement</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Mathematics</span>
<span class="w"> </span><span class="mi">3</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Computer</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">study</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">processes</span><span class="w"> </span><span class="n">that</span><span class="w"> </span><span class="n">interact</span><span class="w"> </span><span class="k">with</span><span class="w"> </span><span class="k">data</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">that</span><span class="w"> </span><span class="n">can</span><span class="w"> </span><span class="n">be</span><span class="w"> </span><span class="n">represented</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="k">data</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">form</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">programs</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Computer</span><span class="w"> </span><span class="n">science</span>
<span class="w"> </span><span class="mi">5</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Geography</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">a</span><span class="w"> </span><span class="n">field</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="n">devoted</span><span class="w"> </span><span class="k">to</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">study</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">lands</span><span class="p">,</span><span class="w"> </span><span class="n">features</span><span class="p">,</span><span class="w"> </span><span class="n">inhabitants</span><span class="p">,</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">phenomena</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">Earth</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">planets</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Geography</span>
<span class="w"> </span><span class="mi">7</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Medical</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">dealing</span><span class="w"> </span><span class="k">with</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">maintenance</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">health</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">prevention</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">treatment</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">disease</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Medical</span><span class="w"> </span><span class="n">science</span>
<span class="p">(</span><span class="mi">4</span><span class="w"> </span><span class="k">rows</span><span class="p">)</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001188270554__a88dc5d3f1fb84cb58b96f25616af48c0">This will also find related words, such as <strong id="EN-US_TOPIC_0000001188270554__b842352706151145">science</strong>, since all these are reduced to the same normalized lexeme.</p>
<p id="EN-US_TOPIC_0000001188270554__a5f9162bc3aa941dd8b02d9fbdb8cf710">The query above specifies that the <strong id="EN-US_TOPIC_0000001188270554__b1547183615117">english</strong> configuration is to be used to parse and normalize the strings. Alternatively, you can omit the configuration parameters, and use the configuration set by <strong id="EN-US_TOPIC_0000001188270554__b19722173710518">default_text_search_config</strong>.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001188270554__s2ed63f8217ee40c3b42a506ddb318cb0"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span>
<span class="normal">15</span>
<span class="normal">16</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SHOW</span><span class="w"> </span><span class="n">default_text_search_config</span><span class="p">;</span>
<span class="w"> </span><span class="n">default_text_search_config</span><span class="w"> </span>
<span class="c1">----------------------------</span>
<span class="w"> </span><span class="n">pg_catalog</span><span class="p">.</span><span class="n">english</span>
<span class="p">(</span><span class="mi">1</span><span class="w"> </span><span class="k">row</span><span class="p">)</span>
<span class="k">SELECT</span><span class="w"> </span><span class="n">id</span><span class="p">,</span><span class="w"> </span><span class="n">body</span><span class="p">,</span><span class="w"> </span><span class="n">title</span><span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">to_tsvector</span><span class="p">(</span><span class="n">body</span><span class="p">)</span><span class="w"> </span><span class="o">@@</span><span class="w"> </span><span class="n">to_tsquery</span><span class="p">(</span><span class="s1">'science'</span><span class="p">);</span>
<span class="w"> </span><span class="n">id</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">body</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">title</span><span class="w"> </span>
<span class="c1">----+-------------------------------------------------------------------------------------------------------------------------+---------</span>
<span class="w"> </span>
<span class="w"> </span><span class="mi">2</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Mathematics</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="n">that</span><span class="w"> </span><span class="n">deals</span><span class="w"> </span><span class="k">with</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">logic</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">shape</span><span class="p">,</span><span class="w"> </span><span class="n">quantity</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">arrangement</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Mathematics</span>
<span class="w"> </span><span class="mi">3</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Computer</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">study</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">processes</span><span class="w"> </span><span class="n">that</span><span class="w"> </span><span class="n">interact</span><span class="w"> </span><span class="k">with</span><span class="w"> </span><span class="k">data</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">that</span><span class="w"> </span><span class="n">can</span><span class="w"> </span><span class="n">be</span><span class="w"> </span><span class="n">represented</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="k">data</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">form</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">programs</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Computer</span><span class="w"> </span><span class="n">science</span>
<span class="w"> </span><span class="mi">5</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Geography</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">a</span><span class="w"> </span><span class="n">field</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="n">devoted</span><span class="w"> </span><span class="k">to</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">study</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">lands</span><span class="p">,</span><span class="w"> </span><span class="n">features</span><span class="p">,</span><span class="w"> </span><span class="n">inhabitants</span><span class="p">,</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">phenomena</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">Earth</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">planets</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Geography</span>
<span class="w"> </span><span class="mi">7</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Medical</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="k">is</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">science</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">dealing</span><span class="w"> </span><span class="k">with</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">maintenance</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">health</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">prevention</span><span class="w"> </span><span class="k">and</span><span class="w"> </span><span class="n">treatment</span><span class="w"> </span><span class="k">of</span><span class="w"> </span><span class="n">disease</span><span class="p">.</span><span class="w"> </span><span class="o">|</span><span class="w"> </span><span class="n">Medical</span><span class="w"> </span><span class="n">science</span>
<span class="p">(</span><span class="mi">4</span><span class="w"> </span><span class="k">rows</span><span class="p">)</span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001188270554__l544e8e68b090433b82ccd684eba86ce8">A more complex example to select the ten most recent documents that contain <strong id="EN-US_TOPIC_0000001188270554__b842352706164037">treatment</strong> and <strong id="EN-US_TOPIC_0000001188270554__b842352706164041">science</strong> in the <strong id="EN-US_TOPIC_0000001188270554__b842352706164045">title</strong> or <strong id="EN-US_TOPIC_0000001188270554__b842352706164047">body</strong> column is as follows:<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001188270554__s965a8eda7d2c4f3c9b924b1724277a6e"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span>
<span class="normal">3</span>
<span class="normal">4</span>
<span class="normal">5</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">SELECT</span><span class="w"> </span><span class="n">title</span><span class="w"> </span><span class="k">FROM</span><span class="w"> </span><span class="n">tsearch</span><span class="p">.</span><span class="n">pgweb</span><span class="w"> </span><span class="k">WHERE</span><span class="w"> </span><span class="n">to_tsvector</span><span class="p">(</span><span class="n">title</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="s1">' '</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">body</span><span class="p">)</span><span class="w"> </span><span class="o">@@</span><span class="w"> </span><span class="n">to_tsquery</span><span class="p">(</span><span class="s1">'treatment &amp; science'</span><span class="p">)</span><span class="w"> </span><span class="k">ORDER</span><span class="w"> </span><span class="k">BY</span><span class="w"> </span><span class="n">last_mod_date</span><span class="w"> </span><span class="k">DESC</span><span class="w"> </span><span class="k">LIMIT</span><span class="w"> </span><span class="mi">10</span><span class="p">;</span>
<span class="w"> </span><span class="n">title</span><span class="w"> </span>
<span class="c1">--------</span>
<span class="n">Medical</span><span class="w"> </span><span class="n">science</span>
<span class="p">(</span><span class="mi">1</span><span class="w"> </span><span class="k">rows</span><span class="p">)</span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001188270554__abcbd89410d8e497a8bc5f9529fd00e85">For clarity we omitted the <strong id="EN-US_TOPIC_0000001188270554__b842352706151339">coalesce</strong> function calls which would be needed to find rows that contain <strong id="EN-US_TOPIC_0000001188270554__b842352706151343">NULL</strong> in one of the two columns.</p>
<p id="EN-US_TOPIC_0000001188270554__a8325300b1bef495bb0f4374eb7607c9d">The preceding examples show queries without using indexes. Most applications will find this approach too slow. Therefore, practical use of text searching usually requires creating an index, except perhaps for occasional ad-hoc searches. </p>
</li></ul>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_06_0087.html">Searching for Texts in Database Tables</a></div>
</div>
</div>
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