hive报错Illegal mix of collations (latin1_bin,IMPLICIT) and (utf8_general_ci,COERCIBLE)
业务发现跑hive任务总是一次成功，第二次无法找到库，需要重新进行hive，查看HiveMetaStore日志报错：
2016-05-11 11:30:32,912 ERROR [pool-3-thread-178]: metastore.RetryingHMSHandler (RetryingHMSHandler.java:invoke(155)) - Retrying HMSHandler after 1000 ms (attempt 1 of 1) with error: javax.jdo.JDOException: Exception thrown when executing query
at org.datanucleus.api.jdo.NucleusJDOHelper.getJDOExceptionForNucleusException(NucleusJDOHelper.java:596)NestedThrowablesStackTrace:
java.sql.SQLException: Illegal mix of collations (latin1_bin,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '='
这个错误什么原因，去查文档说是：结果集中有两种字符集。
mysql> SHOW VARIABLES LIKE 'character_set_%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | latin1 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
mysql> SHOW global VARIABLES LIKE 'character_set_%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
mysql> SHOW VARIABLES LIKE 'collation_%';
+----------------------+-------------------+
| Variable_name | Value |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-------------------+
3 rows in set (0.00 sec)
mysql> SHOW global VARIABLES LIKE 'collation_%';
+----------------------+-----------------+
| Variable_name | Value |
+----------------------+-----------------+
| collation_connection | utf8_general_ci |
| collation_database | utf8_general_ci |
| collation_server | utf8_general_ci |
+----------------------+-----------------+
3 rows in set (0.00 sec)
发现global和当前变量不同，应该是my.cnf文件需要设置下。
mysql和字符集有关的变量
character_set_client：客户端请求数据的字符集
character_set_connection：从客户端接收到数据，然后传输的字符集
character_set_database：默认数据库的字符集，无论默认数据库如何改变，都是这个字符集；如果没有默认数据库，那就使用 character_set_server指定的字符集，这个变量建议由系统自己管理，不要人为定义。
character_set_filesystem：把os上文件名转化成此字符集，即把 character_set_client转换character_set_filesystem， 默认binary是不做任何转换的
character_set_results：结果集的字符集
character_set_server：数据库服务器的默认字符集
character_set_system：这个值总是utf8，不需要设置，是为存储系统元数据的字符集
与业务人员沟通后了解到之前有人新建了中文字段的hive表文件，就是因为这个中文导致的问题，中文的问题就是编码的问题。
临时修改：
set character_set_client =utf8;
set character_set_connection =utf8;
set character_set_results =utf8;
SET collation_server = utf8_general_ci
SET collation_database = utf8_general_ci
永久修改：
[root@ambari03 etc]# cat /etc/my.cnf
[client]
socket=/var/lib/mysql/mysql.sock
default-character-set=utf8
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
default-character-set=utf8
init_connect='SET NAMES utf8'
user=mysql
symbolic-links=0
#skip-grant-tables
max_connections=2000
log-bin=mysql-bin
server-id=11
binlog_format = MIXED
[mysql]
no-auto-rehash
default-character-set=utf8
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid