2012 年 7月 24 日随笔档案 - 紫冰龙

删除重复列

摘要： DELETE FROM abc WHERE ROWID IN (SELECT r FROM (SELECT t.ROWID r, ROW_NUMBER( ) OVER ( PARTITION BY empno, ename, job ORDER BY empno, ename, job ) ... 阅读全文

posted @ 2012-07-24 18:02 紫冰龙阅读(133) 评论(0) 推荐(0)

摘要： v$sqltext存储的是完整的SQL,SQL被分割SQL> desc v$sqltextName Null? Type----------------------------------------- -------- ----------------------------ADDRESS RAW(4) ---------HASH_VALUE NUMBER --------- 和 address 一起唯一标志一条sqlCOMMAND_TYPE NUMBERPIECE NUMBER ---------- 分片之后的顺序编号SQL_TEXT VARCHAR2(64) ----------- 阅读全文

posted @ 2012-07-24 18:00 紫冰龙阅读(211) 评论(0) 推荐(0)

sql trace

摘要： EXECUTE DBMS_MONITOR.SESSION_TRACE_ENABLE(573,63285)EXECUTE dbms_monitor.session_trace_disable(573,63285); 阅读全文

posted @ 2012-07-24 18:00 紫冰龙阅读(66) 评论(0) 推荐(0)

imp命令参数

摘要： imp 命令参数index=n 不导索引 commit=y 以buffer数量为单位提交.如果多数据量小使用N.这样提交会以表为单位 .保证数据一致性buffer=1000000imp userid=\'/ as sysdba\' full=y rows=n indexes=n Constraints=y grants=y buffer=10240000 ignore=y commit=y feedback=10000 file=exp_meta_001.dmp, exp_meta_002.dmp, exp_meta_003.dmp log=imp_f.log statisti 阅读全文

posted @ 2012-07-24 18:00 紫冰龙阅读(1233) 评论(0) 推荐(0)

db link

摘要：今天需要创建一个database link. 先是在本地做了tnsnames.ora条目然后在数据库的sys下按如下命令创建:create public database link lnums connect to ums identified by xxxxxx using 'rac1';这个命令我以为会创建一个全局的lnums link每个用户都可以使用.结果在ums2用户使用此链接时无反应.最后又在ums2下创建另一个db linkcreate database link lnums2 connect to ums identified by xxxxxx using 阅读全文

posted @ 2012-07-24 18:00 紫冰龙阅读(163) 评论(0) 推荐(0)

11g中改用memory_target

摘要： shm /dev/shm tmpfs defaults,size=500M 0 0把上面的这句写到/etc/fstab中 ,然后mount /dev/shmoracle中应该修改这些参数memory_max_target = 500M scope=spfile;sga_max_size=500M scope=spfile;memory_target=500m;sga_target=0;pga_aggregate_target=0 阅读全文

posted @ 2012-07-24 18:00 紫冰龙阅读(165) 评论(0) 推荐(0)

关闭11g新特性

摘要： alter system set event= '10949 trace name context forever, level 1' scope=spfile;alter system set audit_trail=none;ORA-10949: Disable autotune direct path read for full table scan禁止sql tuning advisorBEGIN DBMS_AUTO_TASK_ADMIN.disable( client_name => 'sql tuning advisor', operation 阅读全文

posted @ 2012-07-24 17:57 紫冰龙阅读(313) 评论(0) 推荐(0)

导出当天的sql文本

摘要： declare f utl_file.file_type; buffe varchar2(30000); offest int := 1; amount int;begin f := utl_file.fopen('TEST', 'aa.sql', 'w', 30000); for x in (select sql_fulltext, last_load_time from v$sql where to_date(last_load_time, 'yyyy-mm-dd/hh24:mi:ss') > ... 阅读全文

posted @ 2012-07-24 17:57 紫冰龙阅读(188) 评论(0) 推荐(0)

vmstat详解

摘要： Procs r: The number of processes waiting for run time. 等待CPU的进程数 b: The number of processes in uninterruptible sleep. 不可中断睡眠的进程数 Memory swpd: the amount of virtual memory used. ... 阅读全文

posted @ 2012-07-24 17:57 紫冰龙阅读(133) 评论(0) 推荐(0)

查看执行计划

摘要： 1.SQL> set autotrace on explainSQL> select * from dual;2.SQL> explain plan for select * from dual;SQL> select * from table(DBMS_XPLAN.display);3、启用SQL_TRACE跟踪所有后台进程活动：全局参数设置：..OracleHome/admin/SID/pfile中指定: SQL_TRACE = true (10g)当前session中设置：SQL> alter session set SQL_TRACE=true;SQL&g 阅读全文

posted @ 2012-07-24 17:57 紫冰龙阅读(119) 评论(0) 推荐(0)

统计信息收集

摘要：手动收集DBMS_STATS.GATHER_TABLE_STATS ( ownname =>'CMS', tabname =>'T_FULLWHT', cascade =>true);自动收集可查询如下表:dba_scheduler_windowsSELECT owner,job_name,state,last_start_date,last_run_duration,failure_countFROM dba_scheduler_jobs WHERE job_name = 'GATHER_STATS_JOB';SELECT l 阅读全文

posted @ 2012-07-24 17:54 紫冰龙阅读(164) 评论(0) 推荐(0)

test

摘要： #include <iostream>#include <string>#include <algorithm>using namespace std;int main(){ string str1("we are here!"); string str2(str1); reverse(&str1[0],&str1[0]+12); cout <<str1<<endl; copy(&str1[0],... 阅读全文

posted @ 2012-07-24 17:15 紫冰龙阅读(110) 评论(0) 推荐(0)

Qqjue

公告