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• RMAN备份时数据库当机的浅薄理解，欢迎拍砖

  2008-02-14 12:00:11   /   Oracle数据库管理

  使用OS backup，如果备份时数据库当掉，数据库无法再正常开启，需要进行end backup才可以。那RMAN备份的时候是否也要注意这个呢。下面进行测试。RMAN> backup database;另一个SESSION执行SQL> shutdown abort;ORACLE instance shut down.结果发现RMAN备份报错Starting backup at 2008-02-14 10:43:21using channel ORA_DISK_1channel ORA_DISK_1: starting full datafile backupsetchannel ORA_DISK_1: specifying datafile(s) in backupsetinput datafile fno=

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• 为什么RMAN启用并行备份反而速度比常规备份更慢呢？

  2008-02-13 10:51:18   /   Oracle数据库管理

  数据库版本 9.2.0.4 os rehat as 4.0RMAN> configure device type disk clear;old RMAN configuration parameters:CONFIGURE DEVICE TYPE DISK PARALLELISM 3 BACKUP TYPE TO BACKUPSET;RMAN configuration parameters are successfully reset to default valuereleased channel: ORA_DISK_1released channel: ORA_DISK_2released channel: ORA_DISK_3RMAN> backup database;Starting backup at 2008-02-04 14:28:07allocated channel: ORA_DISK_1channel ORA_DISK_1: sid=159 devtype=DISKchannel ORA_

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• 新用户无法连接上数据库，ora-03113错误

  2008-02-12 14:11:58   /   Oracle数据库管理

  用户端报错ora-03113 end-of-file on communication channelalert.log没有发现任何报错，在udump里面发现有很多*** 2008-02-04 19:01:46.046error 18 creating virtual circuit*** 2008-02-04 19:01:57.219error 18 creating virtual circuit*** 2008-02-04 19:02:25.298error 18 creating virtual circuit*** 2008-02-04 19:02:44.564error 18 creating virtual circuit*** 2008-02-04 19:03:09.737数据库版本9.2.0.4 使用了MTSsessionsinteger2000mts_ses

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• windows下打patch的命令？

  2008-01-30 10:56:09   /   Oracle数据库管理

  windows2003下用不了opatch apply，请问如何做啊

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• 求救啊！SQL走HASH JOIN ，却不走NESTED 导致执行速度很慢

  2008-01-29 10:54:04   /   Oracle数据库管理

  SQL 如下：sql: SELECT b.pallet_noFROM sajet.g_sn_status a, sajet.g_pack_pallet bWHERE a.model_id = :b2AND a.pallet_no = b.pallet_noAND b.terminal_id = :b1AND b.close_flag = 'N'AND ROWNUM = 1problem: a table have 20000000 records b table have 42155 recordsusing hash join ,query very slow but using nested loop get result very fast.ISSUE VERIFICATION===================SQL> SELECT b.pallet_no2 FROM sajet.g_sn_status a, sajet.g_pack_pallet b3 WHERE a.m

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• 严重问题：dbms_stats完全分析后获得的统计数完全错误，大家帮帮忙

  2008-01-28 10:54:27   /   Oracle数据库管理

  我使用如下命令分析表和索引exec dbms_stats.gather_table_stats(ownname=> 'SAJET', tabname=> 'G_SN_STATUS',estimate_percent=>100,cascade=>true,method_opt => 'FOR ALL COLUMNS SIZE 1')分析结束后我查询索引信息。select num_rows,distinct_keys from dba_indexeswhere table_name='G_SN_STATUS'and index_name='G_SN_STATUS_PALLET'NUM_ROWS DISTINCT_KEYS22525290 693发现distinct_key为693条，强烈怀疑这个数值手动确认：select pallet_no,count(*) from g_sn_statusgroup by p

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• hash表建在哪部分内存中SGA还是PGA啊

  2008-01-25 19:41:25   /   Oracle数据库管理

  求救，一段SQLSELECTb.pallet_noFROM sajet.g_sn_status a, sajet.g_pack_pallet bWHERE a.model_id = '1000083350'AND a.pallet_no = b.pallet_noAND b.terminal_id = '10000977'AND b.close_flag = 'N'and rownum =1此时走HASH，发现很慢但是走nested却很快SELECT /*+USE_NL(b,a)*/ b.pallet_noFROM sajet.g_sn_status a, sajet.g_pack_pallet bWHERE a.model_id = '1000083350'AND a.palle

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• 介质恢复失败后无法继续进行

  2008-01-25 08:56:15   /   Oracle数据库管理

  开始介质恢复途中失败，出现*** 2008-01-24 12:51:52.000*** SESSION ID:(2.1) 2008-01-24 12:51:52.000KCF: write/open error block=0x2b890 online=1file=50 U:\ORADATA\SYSTRAVELIDX06.ORAerror=27069 txt: 'OSD-04026: Invalid parameter passed. (OS 178320)'KCF: write/open error block=0x2d783 online=1file=50 U:\ORADATA\SYSTRAVELIDX06.ORAerror=27069 txt: 'OSD-04026: Invalid parameter passed. (OS 186243)'KCF: write/open error block=0x34c7b online=1file=50 U:\ORAD

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• 为什么此SQL必须修改optimizer才能使用索引。

  2008-01-24 13:29:59   /   Oracle数据库管理

  数据库 9I OS windows2003 相关的表及索引已经进行了完全分析11:57:04 SQL> alter session set optimizer_index_cost_adj=10012:00:002;会话已更改。已用时间:00: 00: 00.0112:00:01 SQL> SELECT12:00:152D.REASON_CODE, D.REASON_DESC, D.ENABLED, COUNT(REASON_CODE) CNT12:00:153FROM SAJET.G_SN_DEFECT A,12:00:154SAJET.G_SN_REPAIR B,12:00:155SAJET.SYS_DEFECTC,12:00:156SAJET.SYS_REASOND12:00:157WHERE A.RECID = B.RECID

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• SQL 使用CBO出错

  2008-01-23 20:17:38   /   Oracle数据库管理

  SQL 如下SELECTD.REASON_CODE, D.REASON_DESC, D.ENABLED, COUNT(REASON_CODE) CNTFROM SAJET.G_SN_DEFECT A,SAJET.G_SN_REPAIR B,SAJET.SYS_DEFECTC,SAJET.SYS_REASONDWHERE A.RECID = B.RECIDAND A.DEFECT_ID = C.DEFECT_IDAND C.DEFECT_CODE = '29'AND B.REASON_ID = D.REASON_IDGROUP BY D.REASON_CODE, D.REASON_DESC, D.ENABLEDORDER BY CNT DESC执行计划如图plan1就是不走索引，执行的狂慢结果我改下SELECT /*+rule*/D.REASON_CODE, D.REASON_

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