ITPub博客

1、Client-Side Query CacheThis feature enables caching of query result sets in client memory. The cached result set data is transparently kept consistent with any changes done on the server side.Applications leveraging this feature see improved performance for queries which have a cache hit. Additionally, a query serviced by the cache avoids round trips to the server for sending the query and fetching the results. It also reduces the server CPU that would have been consumed for processing the qu

Oracle Database Standard Edition One Oracle Database Standard Edition One delivers unprecedented ease of use, power, and performance for workgroup,department-level, and Web applications. From single-server environments for small business to highly distributed branch environments, Oracle Database Standard EditionOne includes all the facilities necessary to build business-critical applications.[@more@]Oracle Database Standard Edition Oracle Database Standard Edition delivers the unprecedented ease

北京2008年奥运会赞助企业如下： [@more@]奥林匹克全球合作伙伴北京2008合作伙伴 赞助商独家供应商 供应商　　英孚教育水晶石数字科技元培翻译德尔地板奥康立白普华永道盟多

谁有《美国口语大观》的mp3听力资料？能否分享给我，非常感谢！[@more@]

新登陆的客户端无法登陆上数据库，抛了一堆堆栈和memory的异常。赶紧上os主机上，看看是否有告警信息。查了一下告警日志很正常，没有特别的异样信息出现。查询后台进程信息，如下：[oracle@linux3200 log]$ ps -ef |grep ora_[@more@]oracle 7704 1 0 Nov07 ? 00:00:44 ora_pmon_db3200oracle 7706 1 0 Nov07 ? 00:00:06 ora_psp0_db3200oracle 7708 1 0 Nov07 ? 00:00:04 ora_mman_db3200oracle 7710 1 0 Nov07 ? 00:00:19 ora_dbw0_db3200oracle 7712 1 0 Nov07 ? 00:03:44 ora_lgwr_db3200oracle 7714 1 0 Nov07 ? 00:00:32 ora_ckpt_d

DBNEWID is a database utility that can change the internal, unique database identifier (DBID) and the database name (DBNAME) for an operational database. The DBNEWID utility lets you change any of the following:[@more@]Only the DBID of a databaseOnly the DBNAME of a databaseBoth the DBNAME and DBID of a databaseTherefore, you can manually create a copy of a database and give it a new DBNAME and DBID by re-creating the control file, and you can register a seed database and a manually copied datab

If it was going to easy, it never would have started with something called labor!Shouting to make your children obey is like using the horn to steer your car, and you get about the same results.To be in your children’s memories tomorrow, you have to be in their lives today.[@more@]The smartest advice on raising children is to enjoy them while they are still on your side.The best way to keep kids at home is to give it a loving atmosphere and hide the keys to the car.The right temperature in a ho

This document assumes that you are doing the Backup and Recovery basics- Running in Archivelog mode- multiplexing the controlfile- Taking regular backups- Periodically doing a complete restore to test your procedures. [@more@]Questions and Answers1. Turn on block checking.REASON: The aim is to detect, very early the presence of corrupt blocks in the database.This has a slight performance overhead, but Checksums allow Oracle to detect earlycorruption caused by underlying disk, storage system, or

This short article describes several features of Oracle which may be used on new databases to help detect problems as close to when they occur as possible. Some of these features are publicly documented and some are not. All should be used with extreme care.[@more@]DBVERIFY~~~~~~~~ DBVERIFY (also known as DBV) performs similar checks to the block checking described above but it is a stand alone tool which can be run against an Oracle datafile. Most Unix platform

In Oracle databases, corruption in its broadest sense is incorrect information - information that Oracle did not expect to find. This condition can exist in memory, in data blocks, or in the data dictionary, giving rise to the five forms of corruption:Memory (HEAP) corruptionBlock corruptionDictionary corruptionUndo corruptionRedo corruption[@more@]HEAP corruption occurs when a piece of memory is overwritten and this can be caused by an Oracle Bug, an O/S overwrite, or by an application. The cod

上个礼拜在帮忙一同事解决expdp时碰到三个异常错误，今天总结如下：首先遇到的异常如下：[oracle@linux3200 oracle]$ expdp system/wicp_annie@db3200 directory=dir_expdp dumpfile='wicp_all_071026.dmp';[@more@]Export: Release 10.2.0.1.0 - Production on Thursday, 25 October, 2007 20:56:51Copyright (c) 2003, 2005, Oracle. All rights reserved.Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - ProductionWith the Partitioning, OLAP and Data Mining optionsORA-31626: job does not existORA-

最近在将一heap日志表调整为partition的日志表时，发现一个问题，那就是查询分区数据时无法直接按变量来进行查询。过程如下：insert into t_actionlog_backupselect * from t_actionlog partition(v_partition_name)[@more@]其中v_partition_name是我程序中传入的分区名称变量，结果无论我怎么调试都抛异常“ORA-02149: 指定的分区不存在”。我直接在sql提示符下执行都是没问题的。见如下的过程：declarev_partition_name varchar2(20);beginv_partition_name :='p_20071016';insert into t_actionlog_backupselect * from t_actionlog pa

下面是一个linux下磁盘分区的案例，这里只贴出来其中的操作过程，供大家学习！[root@portal3115 ~]# fdisk -lbash: fdisk: command not found[root@portal3115 ~]# /sbin/fdisk -l[@more@]Disk /dev/cciss/c0d0: 291.3 GB, 291331192320 bytes255 heads, 63 sectors/track, 35419 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesDevice Boot Start End Blocks Id System/dev/cciss/c0d0p1 * 1 13 104391 83 Linux/dev/cciss/c0d0p2 14 267 2040255 82 Linux swap/dev/cciss/c0d0p3 268 5379 41062140 83 Linux/dev/cciss/c0d0

三、查询热点块和热点对象statspack报告中latch的竞争比较突出，见如下：Latch Name Requests Misses Sleeps Sleeps 1->4-------------------------- -------------- ----------- ----------- ------------cache buffers chains 105,398,981 27,571 361 27232/317/22NoWait WaiterLatch Name Where Misses Sleeps Sleeps------------------------ -------------------------- ------- ---------- --------cache buffers chains kcbrls: kslbegin 0 290 7cache buffers chains kcbgtcr: fast path 0 57 43cache buffers chains kcbgtcr:

二、Parent and Child LatchesMost internal Oracle data structures that are protected by latches are protected by only one latch. However, in some cases more than one latch may be used. For example, there may be a number of library cache latches protecting different groups of objects in the library cache, and separate cache buffers chains latches are used to protect each of the database buffer cache hash chains.[@more@]Whenever a number of latches may be used to protect different parts of a struct

一、Latch and LockLatches are the more restrictive mechanism, because they do not allow multiple processes to inspect the protected data structure at the same time—they provide for exclusive access only.[1] Locks allow for better concurrency, because they may be held in a shared mode when the data structure is simply being inspected.[1] This is a simplification. The redo copy latches can be shared, but this is hardware dependent.[@more@]Another significant difference between locks and latches i

Waits are timed if and only if the TIMED_STATISTICS parameter is set to TRUE.Let me endorse what others have said before, that the overhead of timed statistics is negligible. If you need to convince yourself, use the SET TIMING ON command in SQL*Plus to measure the elapsed time of a benchmark query. Use an otherwise idle system and take ten or more measurements with and without timed statistics. You will be hard pressed to discern any significant difference.[@more@]Without timed statistics, Orac

A lecturer was giving a lecture to his student on stress management. He raised a glass of water and asked the audience, ”How heavy do you think this glass of water is?”The students’ answers ranged from 20g to 500g.[@more@]“It does not matter on the absolute weight. It depends on how long you hold it. If I hold it for a minute, it is OK. If I hold it for an hour, I will have an ache in my right arm. If I hold it for a day, you will have to call an ambulance. It is the exact same weight, but t

It has been so bitterly cold here in Pennsylvania.I can’t remember a winter being as cold as this, but I’m sure there were colder days.Even though the daylight hours are growing longer minute by minute, it’s easy to find an excuse not to go out unless you absolutely must, but then again I often have to push myself to accomplish things.[@more@]People I speak to have been in all kinds of nasty moods. They say they’re “under the weather,” not feeling good about this time of year.As I stood ou

因一现网问题需将特定日期内的表日志数据导出供分析，我协助提供了如下的shell脚本：[@more@]#!/usr/bin/shcd /oracle#create usersqlplus -s /nolog <<EOF >/dev/nullconnect portal/portaldrop table op_log_syh;create table op_log_syh as select * from op_log where to_char(op_date,'yyyymmdd') in ('20071008','20071009','20071010','20071011');exit;EOFecho 'Geted the need data from table OP_LOG.'$ORACLE_HOME/bin/exp portal/portal file=/oracle/op_log_syh.dmp tables=op_log_syh consistent=y buffer=5000000