pig-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Pig Wiki] Update of "PigExecutionModel" by UtkarshSrivastava
Date Tue, 22 Jan 2008 07:26:35 GMT
Dear Wiki user,

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

The following page has been changed by UtkarshSrivastava:
http://wiki.apache.org/pig/PigExecutionModel

------------------------------------------------------------------------------
  Each of the above logical operators will translate to a physical operator (in many cases,
the physical operator will be shared between backends, as shown in the above table).
  
  One physical operators have been linked together into a query plan, they must be executed.
There is a choice of mainly 2 models for execution (assume that data flows downwards in an
execution plan):
+ 
+ attachment:simple.png
  
   1. '''Push''': Operator A pushes data to B that operates on it, and pushes the result 
to C.
   2. '''Pull''': Operator C asks B for its next data item. If B has nothing pending to return,
it asks A. When A returns a data item, B operates on it, and finally returns the result to
C.

Mime
View raw message