clickhouse常用sql

1、慢查询监控

SELECTuser,formatDateTime(query_start_time, '%Y%m%d %T') AS start_time,query_duration_ms / 1000 AS query_duration_s,query,memory_usage / 1024 / 1024 / 1024 AS memory_usage_g,result_rows ,formatReadableSize(result_bytes) AS result_bytes,read_rows ,read_bytes / 1024 / 1024 /1024 AS read_bytes_g,written_rows ,written_bytes / 1024 / 1024 /1024 AS written_bytes_gFROM system.query_log
WHERE type = 2
and query_start_time>=today()
ORDER BY query_duration_s DESC
LIMIT 10

2、清空查询日志

ALTER table system.query_log delete WHERE 1=1;

3、查看数据压缩率

selectsum(rows) as "总行数",formatReadableSize(sum(data_uncompressed_bytes)) as "原始大小",formatReadableSize(sum(data_compressed_bytes)) as "压缩大小",round(sum(data_compressed_bytes) / sum(data_uncompressed_bytes) * 100, 0) "压缩率"
from system.parts;

4、查看表大小

SELECTtable,formatReadableSize(sum(data_compressed_bytes)) AS compressed_size ,formatReadableSize(sum(data_uncompressed_bytes)) AS uncompressed_bytes
FROMsystem.parts
WHEREactiveAND (table LIKE 'data_%')GROUP BY table
order byuncompressed_bytes desc ;

5、查看当前连接数

SELECT * FROM system.metrics WHERE metric LIKE '%Connection';

6、手动合并分区

OPTIMIZE TABLE table [PARTITION partition] [FINAL]

7、添加或者更新TTL

ALTER TABLE table1 MODIFY TTL toDate(time) + toIntervalDay(10)

8、添加多个列

ALTER TABLE table1 ADD COLUMN longcol1 Int64 AFTER col111, ADD COLUMN longcol2 Int64 AFTER longcol1;

9、卸载装载分区

ALTER TABLE table1 DETACH PARTITION '1629111600';
ALTER TABLE table1 ATTACH PARTITION '1629111600';

10、查看表资源占用情况

SELECT database,table,sum(rows) AS `总行数`,formatReadableSize(sum(data_uncompressed_bytes)) AS `原始大小`,formatReadableSize(sum(data_compressed_bytes)) AS `压缩大小`,round((sum(data_compressed_bytes) / sum(data_uncompressed_bytes)) * 100., 2) AS `压缩率/%`
FROM system.parts
GROUP BY database,table
ORDER BY database ASC

11、个列字段占用空间统计

SELECT database, table, column, any(type), sum(column_data_compressed_bytes) AS compressed, sum(column_data_uncompressed_bytes) AS uncompressed, round(uncompressed / compressed, 2) AS ratio, compressed / sum(rows) AS bpr, sum(rows)
FROM system.parts_columns
WHERE active AND database != 'system'
GROUP BY database, table, column
ORDER BY database ASC, table ASC, column ASC

12、查看后台执行的更新语句

SELECTdatabase,table,mutation_id,command,create_time,parts_to_do_names,parts_to_do,latest_fail_reason
FROMsystem.mutations
whereis_done <> 1

13、查看正在执行的查询语句

SELECTquery_id,user,address,elapsed,query
FROMsystem.processes
ORDER BYquery_id ASC

14、kill指定的查询语句

KILL QUERY WHERE query_id='query_id';

15、查看集群分布式信息

select * from system.clusters;

16、改名

rename table TABLE1 to TABLE2;

17、更新数据

ALTER TABLE db.test UPDATE name='ccc' WHERE createTime='2020/2/13';

18、系统事件、查询总次数、insert次数、失败次数

select * from system.events

19、查看建表ddl

SHOW CREATE TABLE table1

20、查看当前查询执行列表

show processlist;

21、压缩率

selectdatabase as `数据库`,table as `表名`,formatReadableSize(size) as `所占磁盘大小`,formatReadableSize(data_uncompressed_bytes)  as `原始大小`,formatReadableSize(data_compressed_bytes)  as `压缩大小`,compress_rate as `压缩率`,rows as `行数`,days as `存在天数`,formatReadableSize(avgDaySize) as `平均每天的大小`
from
(selectdatabase,table,sum(bytes) as size,sum(rows) as rows,min(min_date) as min_date,max(max_date) as max_date,sum(data_uncompressed_bytes) as data_uncompressed_bytes,sum(data_compressed_bytes) as data_compressed_bytes,(data_compressed_bytes / data_uncompressed_bytes) * 100 as compress_rate,max_date - min_date as days,size / (max_date - min_date) as avgDaySizefrom system.partswhere active and database = 'ds'and table = 'table'group bydatabase,table
)

clickhouse常用sql相关推荐

clickhouse 常用函数算数函数时间函数日期函数字符串函数比较函数数据类型函数逻辑函数类型转换函数替换函数数组函数随机函数编码函数 UUID URL IP 函数
clickhouse 常用函数算数函数时间函数日期函数字符串函数比较函数数据类型函数逻辑函数类型转换函数替换函数数组函数随机函数编码函数 UUID URL IP 函数算数函数 ...
客快物流大数据项目（九十七）：ClickHouse的SQL语法
文章目录 ClickHouse的SQL语法一.常用的SQL命令
mysql备份数据库语句6_13.4 MySQL用户管理；13.5 常用sql语句；13.6 MySQL数据库备份恢复...
扩展 : SQL语句教程什么是事务?事务的特性有哪些? 根据binlog恢复指定时间段的数据 mysql字符集调整使用xtrabackup备份innodb引擎的数据库 innobackupex ...
oracle批量更新数据从另一表_常用SQL系列之（五）：多表和禁止插入、批量与特殊更新等...
本系统为@牛旦教育IT课堂在微头条上的内容, 为便于查阅,特辑录于此,都是常用SQL基本用法.. 前两篇连接: (一):SQL点滴(查询篇):数据库基础查询案例实战 (二):SQL点滴(排序篇):数据 ...
mysql用户管理，常用sql语句，mysql数据库备份恢复
2019独角兽企业重金招聘Python工程师标准>>> mysql用户管理 grant all on . to 'user1' identified by 'passwd'; gra ...
db2dual_DB2常用SQL的写法(持续更新中...)
DB2常用SQL的写法(持续更新中...) -- Author: lavasoft -- Date : 2006-12-14 -- 创建一个自定义单值类型 create distinct typ ...
MySQL用户管理、常用sql语句、数据库备份
13.4 MySQL用户管理创建用户并授权指定登录IP [root@centos-01linux ~]# mysql -uroot -p Enter password: Welcome to th ...
55：Mysql用户管理|常用sql语句|mysql数据库备份恢复
2019独角兽企业重金招聘Python工程师标准>>> 1.Mysql用户管理: 场景,为了安全,新建的站点,创建新的用户,或者给已有用户授权,对某个库或者某个表有权限: 语法: g ...
mysql @pdept_MySQL 基本管理与常用sql 归结
备份恢复的策略 1.确定要备份表的存储引擎是事务还是非事务的,不同的引擎备份方式在处理数据一致性方面是不大一样的. 2.确定使用全备份还是增量备份.全备份的优点是备份保持最新备份,恢复的时候可以花费 ...

clickhouse常用sql

clickhouse常用sql相关推荐

最新文章

热门文章