Fwd: Starting off with the development

And I wanted to know what type of data structures are created by the parser / planner and how are they read by the
executor.<br /><br />I know that it is some sort of tree. But how many child nodes are there in a node on the tree and
whatstructure is the NODE itself of? <br /><br />Which files should I look into to get these details?<br /><br
/>Thanks<br/><br />-Vaibhav <br />