title: How do indexes speed up searches?
body: <p>How do indexes help in speeding up searching for data based on specific criteria?</p>
  
  <p>If there's a table with 6 columns and none of them are indexed, the program has to check all table rows.</p>
  
  <p>Indexing involves creating another separate table with just two columns, the id and the column you want indexed.</p>
  
  <p>What I don't understand, is how does that help the application do faster searches? It doesn't read the entire 6 column table, but it still has to read the entire 2 column table, right? Which has the same number of rows...</p>