文中使用的Oracle版本为10g。
1. 查找当前表级锁
select sess.sid,
sess.serial#,
lo.oracle_username,
lo.os_user_name,
ao.object_name,
lo.locked_mode
from v$locked_object lo,
dba_objects ao,
v$session sess
where ao.object_id = lo.object_id
and lo.session_id = sess.sid;- 杀掉锁表进程
alter system kill session '436,35123';- RAC环境中锁查找
SELECT inst_id,
DECODE(request,0,'Holder: ','Waiter: ')||sid sess,
id1, id2, lmode, request, type,block,ctime
FROM GV$LOCK
WHERE (id1, id2, type) IN
(SELECT id1, id2, type FROM GV$LOCK WHERE request>0)
ORDER BY id1, request;- 监控当前数据库谁在运行什么
select osuser, username, sql_text
from v$session a, v$sqltext b
where a.sql_address =b.address
order by address, piece;- 使用CPU多的用户session
select a.sid,spid,status,
substr(a.program,1,40) prog,
a.terminal,osuser,value/60/100 value
from v$session a,v$process b,v$sesstat c
where c.statistic#=12 and
c.sid=a.sid and
a.paddr=b.addr
order by value desc;- 查看死锁信息
SELECT (SELECT username
FROM v$session
WHERE SID = a.SID) blocker, a.SID, 'is blocking',
(SELECT username
FROM v$session
WHERE SID = b.SID) blockee, b.SID
FROM v$lock a, v$lock b
WHERE a.BLOCK = 1
AND b.request > 0
AND a.id1 = b.id1
AND a.id2 = b.id2;- 查询具有最高等待的对象
SELECT o.OWNER,o.object_name, o.object_type, a.event,
SUM (a.wait_time + a.time_waited) total_wait_time
FROM v$active_session_history a, dba_objects o
WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
AND a.current_obj# = o.object_id
GROUP BY o.OWNER,o.object_name, o.object_type, a.event
ORDER BY total_wait_time DESC;SELECT a.session_id, s.osuser, s.machine, s.program, o.owner,
o.object_name,o.object_type, a.event,
SUM (a.wait_time + a.time_waited) total_wait_time
FROM v$active_session_history a, dba_objects o, v$session s
WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
AND a.current_obj# = o.object_id
AND a.session_id = s.SID
GROUP BY o.owner,
o.object_name,o.object_type,
a.event,a.session_id,
s.program, s.machine,s.osuser
ORDER BY total_wait_time DESC;- 查询当前连接会话数
select s.value,s.sid,a.username
from v$sesstat S,v$statname N,v$session A
where n.statistic#=s.statistic#
and name='session pga memory'
and s.sid=a.sid
order by s.value;- 等待最多的用户
SELECT s.SID, s.username,
SUM (a.wait_time + a.time_waited) total_wait_time
FROM v$active_session_history a, v$session s
WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
GROUP BY s.SID, s.username
ORDER BY total_wait_time DESC;- 等待最多的会话
SELECT a.program, a.session_id, a.user_id,
d.username, s.sql_text,
SUM (a.wait_time + a.time_waited) total_wait_time
FROM v$active_session_history a, v$sqlarea s, dba_users d
WHERE a.sample_time BETWEEN SYSDATE - 30 / 2880 AND SYSDATE
AND a.sql_id = s.sql_id
AND a.user_id = d.user_id
GROUP BY a.program, a.session_id, a.user_id, s.sql_text, d.username;- 查看消耗资源最多的SQL
SELECT hash_value, executions,
buffer_gets, disk_reads,parse_calls
FROM V$SQLAREA
WHERE buffer_gets > 10000000 OR disk_reads > 1000000
ORDER BY buffer_gets + 100 * disk_reads DESC;select se.username,
se.sid,
su.extents,
su.blocks * to_number(rtrim(p.value)) as Space,
tablespace,
segtype,
sql_text
from v$sort_usage su, v$parameter p, v$session se, v$sql s
where p.name = 'db_block_size'
and su.session_addr = se.saddr
and s.hash_value = su.sqlhash
and s.address = su.sqladdr
order by se.username, se.sid- 查看某条SQL语句的资源消耗
SELECT hash_value,buffer_gets,disk_reads,
executions,parse_calls
FROM V$SQLAREA
WHERE hash_Value = 228801498
AND address = hextoraw('CBD8E4B0');- 查询会话执行的实际SQL
SELECT a.SID,a.username,s.sql_text
FROM v$session a, v$sqltext s
WHERE a.sql_address = s.address
AND a.sql_hash_value = s.hash_value
AND a.status = 'ACTIVE'
ORDER BY a.username, a.SID, s.piece;- 显示正在等待锁的所有会话
SELECT * FROM DBA_WAITERS;- 查询表空间使用情况
SELECT UPPER(F.TABLESPACE_NAME) "表空间名",
D.TOT_GROOTTE_MB "表空间大小(M)",
D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",
TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,2),'990.99') || '%' "使用比",
F.TOTAL_BYTES "空闲空间(M)",
F.MAX_BYTES "最大块(M)"
FROM (SELECT TABLESPACE_NAME,
ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
FROM SYS.DBA_FREE_SPACE
GROUP BY TABLESPACE_NAME) F,
(SELECT DD.TABLESPACE_NAME,
ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
FROM SYS.DBA_DATA_FILES DD
GROUP BY DD.TABLESPACE_NAME) D
WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
ORDER BY 1;- 查询表空间的free space
select tablespace_name,
count(*) as extends,
round(sum(bytes) / 1024 / 1024, 2) as MB,
sum(blocks) as blocks
from dba_free_space
group by tablespace_name;- 查询表空间的总容量
select tablespace_name, sum(bytes) / 1024 / 1024 as MB
from dba_data_files
group by tablespace_name;- 查询表空间使用率
select total.tablespace_name,
round(total.MB, 2) as Total_MB,
round(total.MB - free.MB, 2) as Used_MB,
round((1 - free.MB / total.MB) * 100, 2) || '%' as Used_Pct
from (select tablespace_name, sum(bytes) / 1024 / 1024 as MB
from dba_free_space
group by tablespace_name) free,
(select tablespace_name, sum(bytes) / 1024 / 1024 as MB
from dba_data_files
group by tablespace_name) total
where free.tablespace_name = total.tablespace_name;- 查询数据库最大连接数
select value
from v$parameter
where name = 'processes';20. 对象不再存在(ORA-08103)解决方法
先查询出“xxx”对象信息
SQL> select obj#,dataobj#,name,type#,owner# from obj$ where name='xxx';
OBJ# DATAOBJ# NAME TYPE# OWNER#
----- ---------- ---------------- ---------- ----------
5368 xxx 5 1
5993 xxx 42 66根据obj#对应的id值精确定位到对象（根据OWNER字段判断对象归属，这个不再详述）
SQL> select obj#,dataobj#,name,type#,owner# from obj$ where obj#=5993;
OBJ# DATAOBJ# NAME TYPE# OWNER#
----- ---------- ---------------- ---------- ----------
5993 xxx 42 66确认obj#对象后使用delete from命令进行删除
SQL> delete from obj$ where obj#=5993;
已删除 1 行。
SQL> commit;
提交完成。提交之后再重新查询对象
SQL> select obj#,dataobj#,name,type#,owner# from obj$ where name='xxx';
OBJ# DATAOBJ# NAME TYPE# OWNER#
----- ---------- ---------------- ---------- ----------
5368 xxx 5 1- 生成10以内随机数语句
select round(to_number(dbms_random.value)*10,0) from dual;- 数字非科学计数法输出
select to_char('65647.2657696732665873677469045687295023',999990.999999999999999) from dual;- 解决ORA-22992问题
在存储过程中使用游标进行数据插入，在执行了一半时抛出以下错误：
ORA-22992 cannot use LOB locators selected from remote tables
可使用
create table <table_name> as select ...或
insert into <table_name> select ...解决这个问题。
- 判断某字段中存在中文
select b.* from <table_name> b where asciistr(b.<field_name>) like '%\%';- 查询资源消耗最多的语句
select se.username,
se.sid,
su.extents,
su.blocks * to_number(rtrim(p.value)) as Space,
tablespace,
segtype,
sql_text
from v$sort_usage su, v$parameter p, v$session se, v$sql s
where p.name = 'db_block_size'
and su.session_addr = se.saddr
and s.hash_value = su.sqlhash
and s.address = su.sqladdr
order by se.username, se.sid- 查看当前数据库最大连接数
select value from v$parameter where name = 'processes';- 设置回滚保留时间
ALTER SYSTEM SET UNDO_RETENTION=<timeout_setting> SCOPE=BOTH;- 去掉回车、换行、空格
-- 去除换行
update <table_name> t set t.<field_name>=replace(t.<field_name>,chr(10),'');
-- 去掉回车
update <table_name> t set t.<field_name>=replace(t.<field_name>,chr(13),'');
-- 去掉空格
update <table_name> t set t.<field_name>=trim(t.<field_name>);- 根据sid查询pid
select pro.spid
from v$session ses,v$process pro
where ses.sid='<sid_code>' and ses.paddr=pro.addr;- 分段导出数据备份
exp based/password
file=/oracle/DataBkup/<dmp_file1>.dmp,
/oracle/DataBkup/<dmp_file2>.dmp,
/oracle/DataBkup/<dmp_file3>.dmp,
/oracle/DataBkup/<dmp_file4>.dmp
filesize=2147483648
owner=<tablespace_name>- 查看正在运行的Job（定时器）
SELECT SID,JOB FROM DBA_JOBS_RUNNING;- 创建表空间
create tablespace <tablespace_name> logging datafile '<dbf_file_path>' size 50m autoextend on ;
alter user <username> quota unlimited on <tablespace_name>; - 查看表空间
-- 表空间使用情况
SELECT UPPER(F.TABLESPACE_NAME) "表空间名",
D.TOT_GROOTTE_MB "表空间大小(M)",
D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",
TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,2),'990.99') || '%' "使用比",
F.TOTAL_BYTES "空闲空间(M)",
F.MAX_BYTES "最大块(M)"
FROM (SELECT TABLESPACE_NAME,
ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
FROM SYS.DBA_FREE_SPACE
GROUP BY TABLESPACE_NAME) F,
(SELECT DD.TABLESPACE_NAME,
ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
FROM SYS.DBA_DATA_FILES DD
GROUP BY DD.TABLESPACE_NAME) D
WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
--and F.TABLESPACE_NAME = '<tablespace>'
ORDER BY 1;
-- 表空间大小以及存放位置
SELECT TABLESPACE_NAME,BYTES/1024/1024 FILE_SIZE_MB,FILE_NAME FROM DBA_DATA_FILES- 额外增加表空间
alter tablespace <tablespace_name> add datafile '<dbf_file_path>' size 2024M;- 删除表空间
DROP USER <username> CASCADE;
DROP TABLESPACE <tablespace_name> INCLUDING CONTENTS AND DATAFILES;- 重新解析表中索引增速
analyze table <table_name> compute statistics for all indexes;- 统计字符出现次数
select length(replace(a.<field_name>, ',', ',,'))-length(a.<field_name>) from <table_name>;- 变更分区信息
alter table <table_name> enable row movement;- 查询表中外键
select * from user_constraints c where c.constraint_type = 'R' and c.table_name = '<table_name>'- dmp导入指定表
imp system/manager@TEST file=d:\daochu.dmp tables=(table1)- 查看正在运行的存储过程
select b.sid,b.SERIAL#
from SYS.V_$ACCESS a, SYS.V_$session b
where a.type = 'PROCEDURE'
and (a.OBJECT like upper('%ZZ_Z%') or a.OBJECT like lower('%ZZ_Z%'))
and a.sid = b.sid
and b.status = 'ACTIVE';- Unix下数据备份
# 先转成oracle用户
su - oracle
#导出命令
$ exp <username>/<password> file=<dmp_file_path> tables=<tables_you_need>- Job（定时器）正确写法
-- 每分钟执行
Interval => TRUNC(sysdate,'mi') + 1/ (24*60)
-- 每天定时执行（每天的凌晨1点执行）
Interval => TRUNC(sysdate) + 1 +1/ (24)
-- 每周定时执行（每周一凌晨1点执行）
Interval => TRUNC(NEXT_DAY(sysdate,'星期一'))+1/24
-- 每月定时执行（每月1日凌晨1点执行）
Interval =>TRUNC(LAST_DAY(SYSDATE))+1+1/24
-- 每季度定时执行（每季度的第一天凌晨1点执行）
Interval => TRUNC(ADD_MONTHS(SYSDATE,3),'Q') + 1/24
-- 每半年定时执行（每年7月1日和1月1日凌晨1点）
Interval => ADD_MONTHS(TRUNC(sysdate,'yyyy'),6)+1/24
-- 每年定时执行（每年1月1日凌晨1点执行）
Interval =>ADD_MONTHS(TRUNC(sysdate,'yyyy'),12)+1/24- 增加临时表空间
alter tablespace TEMP add tempfile '<dbf_file_path>' size 2046M;
alter database tempfile '<dbf_file_path>' autoextend on next 3M maxsize unlimited;- 横表变纵表（行转列）
加入现在有一张表名为“tb”，且tb表中字段为Name（varchar2（12）），Subject（varchar2（128））和Result（int），如下：
Name Subject Result
---------- ----------- -----------
张三 语文 74
张三 数学 83
张三 物理 93
李四 语文 74
李四 数学 84
李四 物理 94现在需要对其进行行转列，我们先看静态SQL的转换
select name 姓名,
max(case subject when '语文' then result else 0 end) 语文,
max(case subject when '数学' then result else 0 end) 数学,
max(case subject when '物理' then result else 0 end) 物理
from tb
group by name如果列字段并不固定，同时又想行转列，这种情况下需要使用函数处理
declare @sql varchar(8000)
set @sql = 'select Name as ' + '姓名'
select @sql = @sql + ' , max(case Subject when ''' + Subject + ''' then Result else 0 end) [' + Subject + ']'
from (select distinct Subject from tb) as a
set @sql = @sql + ' from tb group by name'
exec(@sql) 结果输出为
姓名 语文 数学 物理
---------- ----------- ----------- -----------
李四 74 84 94
张三 74 83 93