hive使用mysql保存metastore
Hive 将元数据存储在 RDBMS 中，有三种模式可以连接到数据库：
1）ingle User Mode： 此模式连接到一个 In-memory 的数据库 Derby，一般用于 Unit Test。
2）Multi User Mode：通过网络连接到一个数据库中，是最经常使用到的模式。
3）Remote Server Mode：用于非 Java 客户端访问元数据库，在服务器端启动一个 MetaStoreServer，客户端利用 Thrift 协议通过 MetaStoreServer 访问元数据库。

Hive默认是采用Derby来存储其Meta信息的,
现在我们需要修改为mysql

1.在mysql专门为hive添加用户

mysql> CREATE USER 'hive'@'hive-mysql' IDENTIFIED BY 'hivepasswd';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'hive'@'hive-mysql' WITH GRANT OPTION;

2.修改配置文件conf/hive-site.xml

<property>  
        <name>hive.metastore.local</name>  
        <value>true</value>  
        <description>controls whether to connect to remove metastore server or open a new metastore server in Hive Client JVM</description>
</property>
<property>  
        <name>javax.jdo.option.ConnectionURL</name>  
        <value>jdbc:mysql://hive-mysql:3306/hive?createDatabaseIfNotExist=true</value>  
        <description>JDBC connect string for a JDBC metastore</description>
</property>
<property>  
        <name>javax.jdo.option.ConnectionDriverName</name>  
        <value>com.mysql.jdbc.Driver</value>  
        <description>Driver class name for a JDBC metastore</description>
</property>
<property>  
        <name>javax.jdo.option.ConnectionUserName</name>  
        <value>hive</value>  
        <description>username to use against metastore database</description>
</property>
<property>  
        <name>javax.jdo.option.ConnectionPassword</name>  
        <value>hivepasswd</value>  
        <description>password to use against metastore database</description>
</property>

3.添加jdbc的jar包

wget http://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java-5.1.11.tar.gz/from/http://mysql.he.net/
tar -xvzf mysql-connector-java-5.1.11.tar.gz
cp mysql-connector-java-5.1.11/*.jar /data/soft/hive/lib

4.启动hive

bin/hive
hive> show tables;

When using MySQL as a metastore I see the error "com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: Specified key was too long; max key length is 767 bytes".

    * This is a known limitation of MySQL 5.0 and UTF8 databases. One option is to use another character set, such as 'latin1', which is known to work.


Hive用MySQL做元数据保存的数据库时，mySQL设置
http://running.iteye.com/blog/910277