oracle dba常用脚本

以下为oracle dba常用的脚本

1、检查数据缓冲区和共享区命中率

1)

declare reads_value number(15); direct_value number(15); lob_value number(15); consical_value number(15); db_value number(15); x number; y number; z number; begin select value into reads_value from v$sysstat where name ='physical reads'; select value into direct_value from v$sysstat where name ='physical reads direct'; select value into lob_value from v$sysstat where name ='physical reads direct (lob)'; select value into consical_value from v$sysstat where name ='consistent gets'; select value into db_value from v$sysstat where name = 'db block gets'; x:=direct_value+lob_value; y:=1-(reads_value-x)/(consical_value+db_value-x); dbms_output.put_line('数据缓冲区命中率是：'||y); if(y>=0.9) then dbms_output.put_line('命中率大于0.9数据缓存大小比较合适'); else dbms_output.put_line('数据缓存命中率小于0.9，请调试db_cache_size大小'); end if; select sum(pinhits-reloads)/sum(pins) into z from v$librarycache; dbms_output.put_line('共享区命中率是：'||z); if(z>=0.9) then dbms_output.put_line('共享区命中率大于0.9大小比较合适'); else dbms_output.put_line('共享区命中率小于0.9，请调试db_cache_size大小'); end if; end;

2)补充（来自于oracle10g 性能调整和优化）

db_cache_size

select sum(decode(name, 'physical reads', value, 0)) phys, sum(decode(name, 'db block gets', value, 0)) gets, sum(decode(name, 'Consistent Gets', value, 0)) con_gets, (1 - (sum(decode(name, 'physical reads', value, 0)) / (sum(decode(name, 'db block gets', value, 0)) + sum(decode(name, 'consistent gets', value, 0))))) * 100 HitRatio from v$sysstat;

数据字典命中命中率

select (1-(sum(getmisses)/sum(gets)))*100 "Hit Ratio" from v$rowcache;

2、检查表空间的是使用情况

select a.tablespace_name,total,free,(total-free)/total used from (select tablespace_name,sum(bytes)/1024/1024 total from dba_data_files group by tablespace_name) a, (select tablespace_name,sum(bytes)/1024/1024 free from dba_free_space group by tablespace_name) b where a.tablespace_name=b.tablespace_name;

3、检查和表空间生成语句

--表空间生成语句，请在sql窗体中执行 select dbms_metadata.get_ddl('TABLESPACE',tablespace_name) from dba_tablespaces; --表生成语句 select dbms_metadata.get_ddl('TABLE',upper('&TABLE_NAME'),upper('&USER_NAME')) from dual;

4、找出系统中cpu消耗和io比较大的语句

select SQL_TEXT,SQL_FULLTEXT from v$sql a where a.HASH_VALUE in (select hash_value from v$sqlarea where buffer_gets>1000000 or disk_reads>1000000/*order by buffer_gets+disk_reads desc*/);

5、找出当前系统中比较慢的sql

①aix中通过topas命令找出cpu系统比较大的pid

②通过sql语句方法找出具体语句

--spid为进程号 select SQL_TEXT,SQL_FULLTEXT,FIRST_LOAD_TIME from v$sql where ADDRESS=(select SQL_ADDRESS from v$session where PADDR=(select ADDR from v$process where spid=&&spid));

6、找出比较多的表空间碎片

select tablespace_name, count(*) chunks , max(bytes/1024/1024) max_chunk from dba_free_space group by tablespace_name;

说明：得分越高，表空间的碎片越大