博客

Mysql版

1、查看所有数据库容量大小

-- 查看所有数据库容量大小
SELECT
    table_schema AS '数据库',
    sum( table_rows ) AS '记录数',
    sum(
    TRUNCATE ( data_length / 1024 / 1024, 2 )) AS '数据容量(MB)',
    sum(
    TRUNCATE ( index_length / 1024 / 1024, 2 )) AS '索引容量(MB)' 
FROM
    information_schema.TABLES 
GROUP BY
    table_schema 
ORDER BY
    sum( data_length ) DESC,
    sum( index_length ) DESC;

2、查看所有数据库各表容量大小

SELECT
    table_schema AS '数据库',
    table_name AS '表名',
    table_rows AS '记录数',
    TRUNCATE ( data_length / 1024 / 1024, 2 ) AS '数据容量(MB)',
    TRUNCATE ( index_length / 1024 / 1024, 2 ) AS '索引容量(MB)' 
FROM
    information_schema.TABLES 
ORDER BY
    data_length DESC,
    index_length DESC;

3、查看指定数据库容量大小

SELECT
    table_schema AS '数据库',
    sum( table_rows ) AS '记录数',
    sum(
    TRUNCATE ( data_length / 1024 / 1024, 2 )) AS '数据容量(MB)',
    sum(
    TRUNCATE ( index_length / 1024 / 1024, 2 )) AS '索引容量(MB)' 
FROM
    information_schema.TABLES 
WHERE
    table_schema = '数据库名';

4.查看指定数据库各表容量大小

SELECT
    table_schema AS '数据库',
    table_name AS '表名',
    table_rows AS '记录数',
    TRUNCATE ( data_length / 1024 / 1024, 2 ) AS '数据容量(MB)',
    TRUNCATE ( index_length / 1024 / 1024, 2 ) AS '索引容量(MB)' 
FROM
    information_schema.TABLES 
WHERE
    table_schema = '数据库名' 
ORDER BY
    data_length DESC,
    index_length DESC;

5.查看指定数据库各表信息

SHOW TABLE STATUS;

oracle版

1、 查看表所占的空间大小

--  不需要DBA权限
SELECT SEGMENT_NAME TABLENAME,(BYTES/1024/1024) MB
,RANK() OVER (PARTITION BY NULL ORDER BY BYTES DESC) RANK_ID  //根据表大小进行排序
FROM USER_SEGMENTS
WHERE SEGMENT_TYPE='TABLE'

-- 需要DBA权限,一般情况下很少会给这么高的权限,可以说这个权限基本没有,所以一般工作中不是DBA的人不会常用到这个命令
SELECT t.tablespace_name, round(SUM(bytes / (1024 * 1024)), 0) ts_size 
FROM dba_tablespaces t, dba_data_files d 
WHERE t.tablespace_name = d.tablespace_name 
GROUP BY t.tablespace_name; 

2、 查看表空间的使用情况

SELECT a.tablespace_name "表空间名称",
       total / (1024 * 1024) "表空间大小(M)",
       free / (1024 * 1024) "表空间剩余大小(M)",
       (total - free) / (1024 * 1024 ) "表空间使用大小(M)",
       total / (1024 * 1024 * 1024) "表空间大小(G)",
       free / (1024 * 1024 * 1024) "表空间剩余大小(G)",
       (total - free) / (1024 * 1024 * 1024) "表空间使用大小(G)",
       round((total - free) / total, 4) * 100 "使用率 %"
FROM (SELECT tablespace_name, SUM(bytes) free
      FROM dba_free_space
      GROUP BY tablespace_name) a,
     (SELECT tablespace_name, SUM(bytes) total
      FROM dba_data_files
      GROUP BY tablespace_name) b
WHERE a.tablespace_name = b.tablespace_name

3、 查看回滚段名称及大小

SELECT segment_name, 
tablespace_name, 
r.status, 
(initial_extent / 1024) initialextent, 
(next_extent / 1024) nextextent, 
max_extents, 
v.curext curextent 
FROM dba_rollback_segs r, v$rollstat v 
WHERE r.segment_id = v.usn(+) 
ORDER BY segment_name; 

4、查看控制文件

SELECT NAME FROM v$controlfile; 

5、查看日志文件

SELECT MEMBER FROM v$logfile; 

6、查看数据库对象

SELECT owner, object_type, status, COUNT(*) count# 
FROM all_objects 
GROUP BY owner, object_type, status; 

7、查看数据库版本

SELECT version 
FROM product_component_version 
WHERE substr(product, 1, 6) = 'Oracle'; 

8、查看数据库的创建日期和归档方式

SELECT created, log_mode, log_mode FROM v$database;