We will also add some more information on that page about the tree walker interface and how it is used to do the optimizations.
From: Zheng Shao
Sent: Tuesday, October 13, 2009 10:42 AM
Subject: Re: Current Hive Optimizer
AST are built by Hive.g (Using antlr).
AST -> OperatorTree is done by SemanticAnalyzer.java.
Optimizations are done by Transformer.java and its sub classes.
Hope this help you get started.
On Tue, Oct 13, 2009 at 10:01 AM, bharath v wrote:
Thanks for your reply Ning ,
I saw that page , but we need some detailed description .. such as how optimizations are carried out .. how ASTs are built etc ..
Do u (or any others) have any idea abt them .. Kindly reply
On Tue, Oct 13, 2009 at 7:10 PM, Ning Zhang wrote:
The design doc in Hive's wiki page provides some high level
descriptions. See http://wiki.apache.org/hadoop/Hive/Design
the "compilation" and "optimization" sections.
On Oct 13, 2009, at 4:09 AM, bharath vissapragada wrote:
Hi all ,
We are trying to work on the Optimizer part of hive . Can anyone
point me to a document/link containing how Hive designs it's query
what meta data it uses , how it optimizes the plans (pushing down
selects etc) ... Iam facing difficulties is reading the source
code , so it would
be nice if any one point me to the link containing the above data or
any document containing the same.
Any help is highly appreciated !