title: mysql 5.7 - Specified key was too long; max key length is 3072 bytes
body: <p>One of my talbe has a multicolumn index with total 1011 characters.
  storage engine is InnoDB.</p>
  
  <p>The same table was working just fine in mysql 5.6.26. but now when i upgraded to mysql 5.7.16 i get error <em>Specified key was too long; max key length is 3072 bytes</em>.</p>
  
  <p>I know there's limist on total size of index. but the question is, why was it working in 5.6 and stopped working in 5.7. Is there some thing i can do without reducing the size of columns.</p>