ORA-04031错误分析和解决

ORA-04031错误分析和解决 

查询v$shared_pool_reserved视图可以判断共享池问题的引发原因：

 

SQL>select FREE_SPACE,AVG_FREE_SIZE,USED_SPACE,AVG_USED_SIZE,REQUEST_FAILURES,LAST_FAILURE_SIZE from v$shared_pool_reserved;

 

FREE_SPACE AVG_FREE_SIZE USED_SPACE AVG_USED_SIZE REQUEST_FAILURES LAST_FAILURE_SIZE

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

2685760 167860 0 0 0 0

 

如果request_failures>0且LAST_FAILURE_SIZE>shared_pool_reserved_min_alloc,那么4031可能是因为共享池包括空间缺少连续的空间所致；考虑加大shared_pool_reserved_min_alloc，并增大shared_pool_reserved_size和shared_pool_size来加大共享池保留空间的可用内存。

如果request_failures>0且LAST_FAILURE_SIZE<shared_pool_reserved_min_alloc,或者request_failures=0且LAST_FAILURE_SIZE<shared_pool_reserved_min_alloc，那么应考虑降低shared_pool_reserved_min_alloc。

 

shared_pool_reserved_min_alloc参数值的查询：

SQL>

column name format a35

column value format 9999999

column ISDEFAULT format a5

column ISMOD format a5

column ISADJ format a5

select

x.ksppinm name,

y.ksppstvl value,

y.ksppstdf isdefault,

decode(bitand(y.ksppstvf,7),1,'modified',4,'system_mod','false') ismod,

decode(bitand(y.ksppstvf,2),2,'true','false') isadj

from

sys.x$ksppi x,

sys.x$ksppcv y

where

x.inst_id = userenv('instance') and

y.inst_id = userenv('instance') and

x.indx = y.indx

and x.ksppinm like '_shared_pool%' ---/**_% 查询所有隐含参数’

/

NAME VALUE ISDEF ISMOD ISADJ

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

_shared_pool_reserved_pct 5 TRUE false false

_shared_pool_reserved_min_alloc 4400 TRUE false false

经验谈：

设置_shared_pool_reserved_min_alloc=4100，不建议设置更低；一般在4100~4400之间。