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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "Hive/DeveloperGuide" by PrasadChakka
Date Fri, 09 Jan 2009 23:50:20 GMT
Dear Wiki user,

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The following page has been changed by PrasadChakka:
http://wiki.apache.org/hadoop/Hive/DeveloperGuide

------------------------------------------------------------------------------
  
  
  === MetaStore ===
+ MetaStore contains metadata regarding tables, partitions and databases. This is used by
Query Processor during plan generation.
+ 
+  * Metastore Server - This is the thrift server (interface defined in metastore/if/hive_metastore.if)
that services metadata requests from clients. It delegates most of the requests underlying
meta data store and the Hadoop file system which contains data.
+  * Object Store - ObjectStore class handles access to the actual metadata is stored in the
SQL store. The current implementation uses JPOX ORM solution which is based of JDA specification.
It can be used with any database that is supported by JPOX. New meta stores (file based or
xml based) can added by implementing the interface MetaStore. FileStore is a partial implementation
of an older version of metastore which may be deprecated soon.
+  * Metastore Client - There are python, java, php thrift clients in metastore/src. Java
generated client is extended with HiveMetaStoreClient which is used by Query Processor (ql/metadta).
This is the main interface to all other Hive components.
+ 
  
  === Query Processor ===
  The following are the main components of the Hive Query Processor:

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