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The following page has been changed by RodrigoSchmidt: http://wiki.apache.org/hadoop/Hive/GettingStarted ------------------------------------------------------------------------------ == Metadata Store == - Metadata is in an embedded Derby database whose location is determined by the + Metadata is in an embedded Derby database whose disk storage location is determined by the hive configuration variable named javax.jdo.option.ConnectionURL. By default - (see conf/hive-default.xml) - this location is ./metastore_db + (see conf/hive-default.xml), this location is ./metastore_db - Right now - in the default configuration, this metadata can only be seen by + Right now, in the default configuration, this metadata can only be seen by one user at a time. Metastore can be stored in any database that is supported by JPOX. The @@ -141, +141 @@ The database schema is defined in JDO metadata annotations file package.jdo at src/contrib/hive/metastore/src/model. - In the future - the metastore itself can be a standalone server. + In the future, the metastore itself can be a standalone server. If you want to run the metastore as a network server so it can be accessed from multiple nodes try HiveDerbyServerMode. == DML Operations == - Loading data from flat files into Hive + Loading data from flat files into Hive: hive> LOAD DATA LOCAL INPATH './examples/files/kv1.txt' OVERWRITE INTO TABLE pokes; Loads a file that contains two columns separated by ctrl-a into pokes table. - 'local' signifies that the input file is on the local system. If 'local' + 'local' signifies that the input file is on the local file system. If 'local' is omitted then it looks for the file in HDFS. The keyword 'overwrite' signifies that existing data in the table is deleted. - If the 'overwrite' keyword is omitted - then data files are appended to existing data sets. + If the 'overwrite' keyword is omitted, data files are appended to existing data sets. NOTES: - * NO verification of data against the schema + * NO verification of data against the schema is performed by the load command. - * if the file is in hdfs it is moved into hive controlled file system namespace. + * If the file is in hdfs, it is moved into the Hive-controlled file system namespace. - The root of the hive directory is specified by the option hive.metastore.warehouse.dir + The root of the Hive directory is specified by the option 'hive.metastore.warehouse.dir' - in hive-default.xml. We would advise that this directory be pre-existing before + in hive-default.xml. We advise users to create this directory before trying to create tables via Hive. hive> LOAD DATA LOCAL INPATH './examples/files/kv2.txt' OVERWRITE INTO TABLE invites PARTITION (ds='2008-08-15');
