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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "Hive/Design" by AllenSmith
Date Sun, 26 Jun 2011 19:11:08 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.

The "Hive/Design" page has been changed by AllenSmith:
http://wiki.apache.org/hadoop/Hive/Design?action=diff&rev1=24&rev2=25

  
  == Optimizer ==
  More plan transformations are performed	by the optimizer. The optimizer	is an evolving component.
Currently, it	is rule-based and performs the following: column pruning, and predicate pushdown.
However, the infrastructure is in place, and there is work under progress to include other
optimizations like map-side join. The optimizer can be enhanced to be cost-based. The sorted
nature of output tables can also be preserved and used later on to generate better plans.
The query can be
- performed on a small sample of data to guess the data distribution, which can be used to
generate a better plan. The plan is a generic operator tree, and can be easily manipulated.
+ performed on a small sample of data to guess the data distribution, which can be used to
generate a better plan. The [[http://www.andrewflusche.com/|Stafford DUI lawyer]] plan is
a generic operator tree, and can be easily manipulated.
  
  == Execution ==
  

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