查看所有數據庫大小(通用)
select TABLE_SCHEMA, concat(truncate(sum(data_length)/1024/1024,2),' MB') as data_size,
concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size
from information_schema.tables
group by TABLE_SCHEMA
order by data_length desc;
TABLE_SCHEMA
:數據表所屬的數據庫名。
concat(truncate(sum(data_length)/1024/1024,2),' MB')
:默認字節數轉換爲以M爲單位的保留兩位小數的值
使用數據庫data_analyses,查看其中所有表大小,按大小排序
use data_analyses;
show tables;
select TABLE_NAME,
concat(truncate(data_length/1024/1024,2),' MB') as data_size,
concat(truncate(index_length/1024/1024,2),' MB') as index_size
from information_schema.tables
where TABLE_SCHEMA = 'data_analyses'
group by TABLE_NAME
order by data_length desc;
查看data_analyses數據庫中表的前10行內容
use data_analyses;
select * from code_statistic limit 100;
附帶
查看hdfs使用情況:
- 根目錄下文件佔用磁盤情況:
hdfs dfs -du -h /
- Hdfs文件查看:
hdfs dfs -get /log/map1/* /usr/data
(說明:將hdfs下的/log/map1/下的所有文件全部複製到本地的/usr/data/下 ,使用vi也好,cat也好,tail也好去查看文件內容)