title: Why Sequelize issues "SHOW INDEX FROM `table`"?
body: <p>If you would enable <code>Sequelize</code> logging, you would see that during the "sync" phase and right after creating a table, <code>Sequelize</code> executes <code>SHOW INDEX FROM table</code> query. The question is - why?</p>
  
  <hr>
  
  <p>To be more specific, here is the code I'm executing:</p>
  
  <pre><code>var Sequelize = require('sequelize');
  
  var connection = new Sequelize('demo_schema', 'root', 'password');
  
  var Article = connection.define('article', {
      slug: {
          type: Sequelize.STRING,
          primaryKey: true
      },
      title: {
          type: Sequelize.STRING,
          unique: true,
          allowNull: false
      },
      body:  {
          type: Sequelize.TEXT
      }
  }, {
      timestamps: false
  });
  
  connection.sync({
      force: true,
      logging: console.log
  }).then(function () {
     // TODO
  });
  </code></pre>
  
  <p>Here is the output on the console:</p>
  
  <pre><code>Executing (default): DROP TABLE IF EXISTS `articles`;
  Executing (default): DROP TABLE IF EXISTS `articles`;
  Executing (default): CREATE TABLE IF NOT EXISTS `articles` (`slug` VARCHAR(255) , `title` VARCHAR(255) NOT NULL UNIQUE, `body` TEXT, UNIQUE `articles_title_unique` (`title`), PRIMARY KEY (`slug`)) ENGINE=InnoDB;
  Executing (default): SHOW INDEX FROM `articles`
  </code></pre>