title: SQL: like v. equals performance comparison
body: <p>I have a large table (100 million rows) which is properly indexed in a traditional RDBMS system (Oracle, MySQL, Postgres, SQL Server, etc.).  I would like to perform a SELECT query which can be formulated with either of the following criteria options:</p>
  
  <p>One that can be represented by a single criteria:</p>
  
  <pre><code>LIKE "T40%" 
  </code></pre>
  
  <p>which only looks for matches at the beginning of the string field due to the wildcard</p>
  
  <p>or</p>
  
  <p>One that requires a list of say 200 exact criteria:</p>
  
  <pre><code>WHERE IN("T40.x21","T40.x32","T40.x43")
  </code></pre>
  
  <p>etc.</p>
  
  <p>All other things being equal. Which should I expect to be more performant?</p>