hive修改使用utf8编码支持中文字符集
转载来自葛大力：
1.hive建库语句：
create database amon DEFAULT CHARSET utf8 COLLATE utf8_general_ci;2.hive启动后，修改hive的元数据信息，无需重启mysql和hive就能生效
解决desc命令注释中文乱码：修改hive存储在mysql里的元数据相关信息
1).修改字段注释字符集
alter table COLUMNS_V2 modify column COMMENT varchar(256) character set utf8;
2).修改表注释字符集
alter table TABLE_PARAMS modify column PARAM_VALUE varchar(4000) character set utf8;
3).修改分区表参数，以支持分区键能够用中文表示
alter table PARTITION_PARAMS modify column PARAM_VALUE varchar(4000) character set utf8;
alter table PARTITION_KEYS modify column PKEY_COMMENT varchar(4000) character set utf8;
4).修改索引注解
alter table INDEX_PARAMS modify column PARAM_VALUE varchar(4000) character set utf8;
3.只有修改编码后才加入的中文注释才会正常显示 ，修改编码前已经存在的中文注释不会正常显示
========================建表测试========================
分区表
create table page_view
(
page_id bigint comment '页面ID',
page_name string comment '页面名称',
page_url string comment '页面URL'
)
comment '页面视图'
partitioned by (ds string comment '当前时间，用于分区字段') ;
表字段索引
create index zxz_5_index
on table page_view (page_url)
as 'bitmap'
with deferred rebuild
COMMENT "页面URL"
添加分区
alter table page_view add partition(ds='20190113');
插入数据
insert into page_view partition(ds='20190113') values (1,"王克洲","田慧杰") ;
查看索引
SHOW FORMATTED INDEX ON page_view;
查看表结构
desc page_view;测试结果
4.后来发现hive无法创建中文索引，报错如下：
hive> alter table page_view add partition(ds='20190113开心');
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. MetaException(message:Exception thrown when executing query) 
解决办法如下：
MariaDB [hive]> show create table PARTITIONS;
| PARTITIONS | CREATE TABLE `PARTITIONS` (
`PART_ID` bigint(20) NOT NULL,
`CREATE_TIME` int(11) NOT NULL,
`LAST_ACCESS_TIME` int(11) NOT NULL,
`PART_NAME` varchar(767) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL,
`SD_ID` bigint(20) DEFAULT NULL,
`TBL_ID` bigint(20) DEFAULT NULL,
`LINK_TARGET_ID` bigint(20) DEFAULT NULL,
PRIMARY KEY (`PART_ID`),
UNIQUE KEY `UNIQUEPARTITION` (`PART_NAME`,`TBL_ID`),
KEY `PARTITIONS_N49` (`TBL_ID`),
KEY `PARTITIONS_N50` (`SD_ID`),
KEY `PARTITIONS_N51` (`LINK_TARGET_ID`),
CONSTRAINT `PARTITIONS_FK1` FOREIGN KEY (`TBL_ID`) REFERENCES `TBLS` (`TBL_ID`),
CONSTRAINT `PARTITIONS_FK2` FOREIGN KEY (`SD_ID`) REFERENCES `SDS` (`SD_ID`),
CONSTRAINT `PARTITIONS_FK3` FOREIGN KEY (`LINK_TARGET_ID`) REFERENCES `PARTITIONS` (`PART_ID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
MariaDB [hive]> alter table PARTITIONS modify column `PART_NAME` varchar(767) character set utf8;
ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes
MariaDB [hive]> alter table PARTITIONS modify column `PART_NAME` varchar(100) character set utf8;
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
MariaDB [hive]> alter table PARTITIONS modify column `PART_NAME` varchar(300) character set utf8;
ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes
MariaDB [hive]> alter table PARTITIONS modify column `PART_NAME` varchar(200) character set utf8;
Query OK, 0 rows affected (0.00 sec)
Records: 0 Duplicates: 0 Warnings: 0
MariaDB [hive]> alter table PARTITIONS modify column `PART_NAME` varchar(250) character set utf8;
Query OK, 0 rows affected (0.00 sec)
Records: 0 Duplicates: 0 Warnings: 0
MariaDB [hive]> alter table PARTITIONS modify column `PART_NAME` varchar(260) character set utf8;
ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes另外验证一个小问题，utf8占用三个字节，之前默认是767，我指定250 * 3 = 750可以，但是260*3=780不可以；
再去创建中文分区，发现可以了：
