Oracle常用知识总结(四)

2014-11-24 15:53:23 · 作者: · 浏览: 3
的情况下查找session

SELECT SID, OSUSER, USERNAME, MACHINE, TERMINAL

FROM V$SESSION

WHERE terminal = 'pts/tl' AND machine = 'rgmdbs1';

查找当前被某个指定session正在运行的sql语句。假设sessionID为100

select b.sql_text

from v$session a,v$sqlarea b

where a.sql_hashvalue=b.hash_value and a.sid=100

Sql代码

示例:已知hash_value:3111103299,查询sql语句:

select * from v$sqltext

where hashvalue='3111103299'

order by piece

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 > 10000000OR disk_reads > 1000000

ORDERBY buffer_gets + 100 * disk_reads DESC;

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 = 228801498AND address = hextoraw('CBD8E4B0');

查询sql语句的动态执行计划:

首先使用下面的语句找到语句的在执行计划中的address和hash_code

SELECT sql_text, address, hash_value FROM v$sql t

where (sql_text like '%FUNCTION_T(表名大写!)%')

然后:

SELECT operation, options, object_name, cost FROM v$sql_plan

WHERE address = 'C00000016BD6D248' AND hash_value = 664376056;

查询oracle的版本:

select * from v$version;

查询数据库的一些参数:

select * from v$parameter

查找你的session信息

SELECT SID, OSUSER, USERNAME, MACHINE, PROCESS

FROM V$SESSION WHERE audsid = userenv('SESSIONID');

当machine已知的情况下查找session

SELECT SID, OSUSER, USERNAME, MACHINE, TERMINAL

FROM V$SESSION

WHERE terminal = 'pts/tl' AND machine = 'rgmdbs1';

查找当前被某个指定session正在运行的sql语句。假设sessionID为100

select b.sql_text

from v$session a,v$sqlarea b

where a.sql_hashvalue=b.hash_value and a.sid=100

示例:已知hash_value:3111103299,查询sql语句:

select * from v$sqltext

where hashvalue='3111103299'

order by piece

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 > 10000000OR disk_reads > 1000000

ORDERBY buffer_gets + 100 * disk_reads DESC;

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 = 228801498AND address = hextoraw('CBD8E4B0');

查询sql语句的动态执行计划:

首先使用下面的语句找到语句的在执行计划中的address和hash_code

SELECT sql_text, address, hash_value FROM v$sql t

where (sql_text like '%FUNCTION_T(表名大写!)%')

然后:

SELECT operation, options, object_name, cost FROM v$sql_plan

WHERE address = 'C00000016BD6D248' AND hash_value = 664376056;

查询oracle的版本:

select * from v$version;

查询数据库的一些参数:

select * from v$parameter

查找你的session信息

SELECT SID, OSUSER, USERNAME, MACHINE, PROCESS

FROM V$SESSION WHERE audsid = userenv('SESSIONID');

当machine已知的情况下查找session

SELECT SID, OSUSER, USERNAME, MACHINE, TERMINAL

FROM V$SESSION

WHERE terminal = 'pts/tl' AND machine = 'rgmdbs1';

查找当前被某个指定session正在运行的sql语句。假设sessionID为100

select b.sql_text

from v$session a,v$sqlarea b

where a.sql_hashvalue=b.hash_value and a.sid=100

树形结构connect by 排序:

Sql代码

查询树形的数据结构,同时对一层里面的数据进行排序

SELECT last_name, employee_id, manager_id, LEVEL

FROM employees

START WITH employee_id = 100

CONNECT BY PRIOR employee_id = manager_id

ORDER SIBLINGS BY last_name;

下面是查询结果

LAST_NAME EMPLOYEE_ID MANAGER_ID LEVEL

------------------------- ----------- ---------- ----------

King 100 1

Cambrault 148 100 2

Bates 172 148 3

Bloom 169 148 3

Fox 170 148 3

Kumar 173 148 3

Ozer 168 148 3

Smith 171 148 3

De Haan 102 100 2

Hunold 103 102 3

Austin 105 103 4

Ernst 104 103 4

Lorentz 107 103 4

Pataballa 106 103 4

Errazuriz 147 100 2

Ande 166 147 3

Banda