title: Indexing every column in a table
body: <p>I have a couple of questions regarding MySQL indexing:</p>
  
  <p>1) Is there any speed increase when indexing a table stored in memory?</p>
  
  <p>2) When searching my table I match on column field, would indexing every column defeat the purpose of an index?</p>
  
  <p>Many thanks.</p>