ORACLE常用查询命令，持续更新......

 

查询表空间的使用情况

SELECT a.tablespace_name "表空间名",total 表空间大小,free 表空间剩余大小,(total-free) 表空间使用大小,ROUND((total-free)/total,4)*100 "使用率 %"

FROM (SELECT tablespace_name,SUM(bytes) free FROM DBA_FREE_SPACE GROUP BY ablespace_name ) a,(SELECT tablespace_name,SUM(bytes) total FROM DBA_DATA_FILES GROUP BY tablespace_name) b

WHERE a.tablespace_name=b.tablespace_name

查询临时表空间使用情况

SELECT D.TABLESPACE_NAME,SPACE "SUM_SPACE(M)",BLOCKS SUM_BLOCKS,USED_SPACE "USED_SPACE(M)", ROUND(NVL(USED_SPACE,0)/SPACE*100,2) "USED_RATE(%)",NVL(FREE_SPACE,0) "FREE_SPACE(M)"

FROM (SELECT TABLESPACE_NAME,ROUND(SUM(BYTES)/(1024*1024),2) SPACE,SUM(BLOCKS) BLOCKS FROM DBA_TEMP_FILES GROUP BY TABLESPACE_NAME) D, (SELECT TABLESPACE_NAME,ROUND(SUM(BYTES_USED)/(1024*1024),2) USED_SPACE, ROUND(SUM(BYTES_FREE)/(1024*1024),2) FREE_SPACE FROM V$TEMP_SPACE_HEADER GROUP BY TABLESPACE_NAME) F

WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME(+)

查询锁并杀之

SELECT b.username,b.sid,b.serial#,logon_time FROM v$locked_object a,v$session b WHERE a.session_id = b.sid order by b.logon_time

alter system kill session 'xxx,xxxx';

查看某表的大小

select sum(bytes)/(1024*1024) as
"size(M)" from user_segments where segment_name=upper('&table_name');
查看放在ORACLE的内存区里的表
select table_name,cache from
user_tables where instr(cache,'Y')>0;

查看索引的大小
select sum(bytes)/(1024*1024) as
"size(M)" from user_segments where segment_name=upper('&index_name');

查看表空间的名称及大小
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;
查看表空间物理文件的名称及大小
select tablespace_name, file_id,
file_name,
round(bytes/(1024*1024),0) total_space
from dba_data_files
order by tablespace_name;

oracle数据文件大小限制的公式：
oracle maximum
file size = db_block_size * 4194303  （2^22 = 4194304）
也就是说最大的数据文件大小是由 db_block_size 来决定的，8KB的数据块的数据文件最大为 8K * 4194304 = 32G。【注】以上规则适用于smallfile tablespace 下的数据文件，bigfile tablespace 下的数据文件不受此限制