title: AST vs Postfix Algorithm
body: <p>I am creating a database capable of performing SQL queries. I'm using Flex / Bison to create my AST (abstract syntax tree). 
  For example: select * from table where score> 10 * (age * salary) </p>
  
  <p><img src="https://i.stack.imgur.com/1YeX4.png" alt="enter image description here"></p>
  
  <p>When i evaluate this AST tree, i traverse the tree, starting from the left and then the right sub-tree. </p>
  
  <p>Comparing with muparser (<a href="http://muparser.beltoforion.de/" rel="nofollow noreferrer">http://muparser.beltoforion.de/</a>), it is much faster. Is there any other way to perform this processing? If I use Postfix algorithm (<a href="http://en.wikipedia.org/wiki/Reverse_Polish_notation" rel="nofollow noreferrer">http://en.wikipedia.org/wiki/Reverse_Polish_notation</a>) Will I have better performance? </p>
  
  <p>How traditional databases perform this task?</p>