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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "Hive/Locking" by NamitJain
Date Wed, 05 May 2010 01:31:25 GMT
Dear Wiki user,

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The "Hive/Locking" page has been changed by NamitJain.


  Based on this, the lock	acquired for an	operation is as	follows:
+ ||'''Hive Command''' ||'''Locks Acquired''' ||
+ ||'''select .. T1 partition P1''' ||'''S on T1, S on T1.P1''' ||
+ ||'''insert into T2(partition P2) select .. T1 partition P1''' ||'''S on T2, X on T2.P2,
S on T1, S on T1.P1''' ||
  In order to avoid deadlocks, a very simple scheme is proposed here. All	the objects to be
  are sorted lexicographically, and the required mode lock is acquired. Note that	in some
cases, the
  list of objects may not be known - for eg. in case of dynamic partitions, the list of partitions

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