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1.base  1) 为了让查询优化器(query optimizer)产生最优的执行计划，对象上的statistics一定是要有效的。oracle数据库收集statistics的功能在每个版本都在得到不断的提高    2) 8i中，引入了dbms_sta...

xjprmapp:jfexp:/jfexp>exp monitor/monitor@crmdb tables=dbcustadm.dcustdoc file=dcutdoc.dmp direct=yExport: Release 9.2.0.1.0 - Production on Tue Apr 28 22:49:18 2009Copyright (c) 1982, 2002, Oracle ...

Finding and repairing chained rows is an important part of Oracle administration.  When an Oracle rows expands, it sometimes chains onto multiple data blocks.  Excessive row chaining can cau...

SQL> truncate table bill3g.BF_PAY_FEE_T;Table truncated.Elapsed: 00:00:01.22SQL> insert /*+ append parallel(a 2) */into bill3g.BF_PAY_FEE_T a select * from bss2.BF_PAY_FEE_T@zz where city_code=890;^...

Parameters That Must Be Identical Across All InstancesCertain initialization parameters that are critical at database creation or that affectcertain database operations must have the same value for e...

dba_objects中有object_id和dba_object_id，那V$LOCKED_OBJECT中的object_Id到底应该和哪个对应呢？做个实验来验证下SQL> show userUSER is "SYS"SQL> create table test as select * from tab where 1=2;Table cr...

语句为：select  '20000号拆出来的套餐订购 895'||count(*)from uniteleacc.bb_user_product_info_t a,unitelecrm.bb_service_relation_t b, tsubproduct_item_20000mid d, pitemrolemid cwhere  a.f_use...

DRIVING_SITE Hint The DRIVING_SITE hint instructs the optimizer to execute the query at a different site than that selected by the database. This hint is useful if you are using distributed query opt...

晚上有应用人员说测试库连不了，第一反应是看看/oracle文件系统是否满了，没满，于是再看看alert文件，一堆报错Errors in file /oracle/app/admin/crmkfdb/bdump/crmkfdb_psp0_152212.trc:ORA-27300: OS system dep...

Oracle 10.2.0.1.0在开发环境里面truncate一些列表，速度奇慢。看了一下session等待事件 Local Write Wait- Event# 是60，Class是 User I/O。 上Metalink也没有查到这个等待事件，Google了一下，还是找到了一点解释...

For those of us who review the Oracle installation documentation, we know that Oracle suggests that you configure a substantial amount of swap space. If you have between 1 and 2G RAM, you need to conf...

Using IBM's AIX dialect of UNIX, an I/O bound database server is usually evidenced by a high value in the wa (wait) column of vmstat. In the next listing, we see that 22 percent of the CPU time is bei...

 Now that we know the amount of RAM on our server, we are ready to investigate the RAM and swap disk usage for the Oracle server. Whenever the memory demands of the server exceed that amount of ...

Display RAM Size on HP/UXIn HP/UX, the dmesg command can display memory information:L 5-12dmesgMemory Information:physical page size = 4096 bytes, logical page size = 4096 bytesPhysical: 5242880 K...

在Oracle 9iR2以前，在IBM AIX上使用lv raw（裸设备）作为Oracle数据文件的话，lv头部是存在一个4k的lv管理区的。正因为这个4k的lv头部，会导致8k以及8k以上的Oracle block（Oracle块）在使用这样的lv的时候，或者是...

查了下官方文档：read by other sessionThis event occurs when a session requests a buffer that is currently being read into the buffer cache by another session. Prior to release 10.1, waits for this e...

noarchivelog模式，从backupset中恢复了一个文件，现在库打不开SQL> alter database open;alter database open*ERROR at line 1:ORA-01113: file 4 needs media recoveryORA-01110: data file 4: '/dev/rzz_01_lv'...

HHL-690-1:/oracle/bbed$bbed parfile=par.bbdPassword: BBED: Release 2.0.0.0.0 - Limited Production on Fri Apr 3 23:50:12 2009Copyright (c) 1982, 2007, Oracle.  All rights reserved.*************...

首先看表里的数据SQL> select * from test;         A B---------- ----------         1 ysatnaf    &nb...

建立测试表SQL> create table test(a number(10),b varchar2(100));Table created.SQL> insert into test values(1,'fantasy');1 row created.SQL> insert into test values(2,'daily');1 row created.SQL> in...