监控 SQL 1.监控事例的等待： select event,sum(decode(wait_time,0,0,1)) prev, sum(decode(wait_time,0,1,0)) curr,count(*) from v$session_wait group by event order by 4; 2.回滚段的争用情况： select name,waits,gets,waits/gets ratio from v$rollstat a,v$rollname b where a.us
Oracle常用管理SQL 监控 SQL 1.监控事例的等待： select event,sum(decode(wait_time,0,0,1)) prev, sum(decode(wait_time,0,1,0)) curr,count(*) from v$session_wait group by event order by 4;
Essential SQL on SQL Server 2008 Contents Preface ix Acknowledgments xiii Chapter 1桽tarting Microsoft?SQL Server?2008 1 1.1 Starting Microsoft?SQL Server?2008 and SQL Server ManagementSt udio 3 1.2 Creating a Database in Microsoft?SQL Server?2008 5
Part I: Programming in PL/SQL Part II: PL/SQL Program Structure Part III: PL/SQL Program Data Part IV: SQL in PL/SQL Part V: PL/SQL Application Construction Part VI: Advanced PL/SQL Topics Part VII: Appendixes
Oracle维护常用SQL语句汇总: 如何远程判断Oracle数据库的安装平台 select * from v$version; 查看表空间的使用情况 select sum(bytes)/(1024*1024) as free_space,tablespace_name from dba_free_space group by tablespace_name; SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE,
具体详情请看下文代码分析。
--查询正在执行的SQL语句
SELECT OSUSER 电脑登录身份,
PROGRAM 发起请求的程序,
USERNAME 登录系统的用户名,
SCHEMANAME,
B.Cpu_Time 花费cpu的时间,
STATUS,
B.SQL_TEXT 执行的sql,
B.
FROM V$SESSION A
LEFT JOIN V$SQL B ON A.SQL_ADDRESS = B.ADDRESS
AND A.SQL_HASH_VALUE = B.HASH_VALUE
在SQL优化过程，有时候需要查看哪些SQL具有多个执行计划（Multiple Executions Plans for the same SQL statement），因为同一个SQL有多个执行计划一般意味着代码有问题或某些其它原因，例如，SQL语句使用绑定变量，但是绑定变量的类型或长度可能不一致会导致同一SQL出现不同执行计划。
–查看数据库里面有多个执行计划的SQL语句的SQL_ID
SELECT SQL_ID， COUNT(1) AS PLAN_NUM
FROM V$SQ
