title: Query execution is taking too long
body: <p>I currently have two tables in a database. Called Email and unsuscribed both tables have a column called Email. now I want to compare these two tables and wherever email matches I want to update column in email table called Email_status_id to 2...the query I am using is</p>
  
  <pre><code>UPDATE  Email E
  SET E.Email_status_id = 2
  WHERE 
      E.Email
    IN (
      SELECT 
       U.Email
      FROM 
       UNSUSCRIBED U);
  </code></pre>
  
  <p>I am currently using mysql. </p>
  
  <p>email table has 2704569 rows of Email
  and unsuscribed table has 12102 rows of Email</p>
  
  <p>the query execution time is taking forever....</p>
  
  <p>any suggestion to reduce query execution time...</p>