title: Is it OK to nest database views?
body: <p>In the world of oracle, I have the impression that views based on other views are considered to be bad practice. I myself have complained about this when the trying to solve performance issues and the nesting seemed excessive and hid away unneeded complexity in the underlying views. Now I find myself in the situation of thinking that it may not be so clear-cut:</p>
  
  <p>I have users who very specifically need the accounting numbers from one view to match those of another that does further processing on them. If they ever change anything in one, they want the other to reflect that immediately, without anyone having to think of this requirement in a few years time and reports showing non-matching numbers while they figure things out.</p>
  
  <p>Is it ok to nest views in this case?</p>
  
  <p>Does it change things if the inner view contains a further, important view that contains relevant prices (i.e. you're "always" supposed to use this view when determining prices)?</p>