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摘要：Question:What is between between "unique index vs non-unique index". Which one is faster. The customer using non-unique and sql is getting delay If we change tp non-unique. Is it work ?Answer:Indexes ... 阅读全文

摘要：OPROCD introduced in 10.2.0.4 Linux and other Unix platform. Fencing Cluster handling of nodes that should not have access to shared resources STONITH – Power cycle the node PCW – nodes fence themselv... 阅读全文

摘要：Active Session History (ASH) performed an emergency flush. This may mean that ASH is undersized. If emergency flushes are a recurring issue, you may consider increasing ASH size by setting the value o... 阅读全文

摘要：Single resource deadlock: blocking enqueue which blocks itself, f 0Single resource deadlock: blocking enqueue which blocks itself, f 0Granted global enqueue 0xd8578490----------enqueue 0xd8578490-----... 阅读全文

摘要：在分布式事务环境中数据库的SCN可能瞬间暴增，这种行为被称作SCN jump in distributed transaction，注意这种现象是正常的。在发生分布式事务的2个数据库中，SCN较低的DB会将SCN和较高的那个数据库同步，这有时候会造成我们的一些误解认为可能是Hot backup等操作引起了SCN的猛增。我们来具体看一下这种现象:SQL> select * from v$versio... 阅读全文

摘要：1. The Total size of the log buffer is determined by LOG_BUFFER parameter.2. Only Server process may pin a data block in exclusive mode.3. LGWR writes to the redo log files when: The redo log buff... 阅读全文

摘要：Scriptset echo offset feedback offcolumn timecol new_value timestampcolumn spool_extension new_value suffixselect to_char(sysdate,'Mondd_hh24mi') timecol,'.out' spool_extension from sys.dual;column ou... 阅读全文

摘要：通过下图定义的规则，可确定分区索引类型:Hash Global分区索引介绍HASH-Partitioned Global索引是Oracle 10g开始提供的新特性。而在以前的版本中，Oracle只支持Range-Partitioned Global索引。HASH-Partitioned Global索引的好处如下：比Range-Partitioned Global索引易于实施。HASH-Part... 阅读全文

摘要：以下脚本用于列出Oracle Buffer Cache的详细信息:REM List Buffer Cache DetailsSET LINESIZE 200 PAGESIZE 1400SELECT /*+ ORDERED USE_HASH(o u) MERGE */ DECODE(obj#, NULL, to_char(bh.obj), u.name ||... 阅读全文

摘要：以下脚本用以列出Database-instance-session的NLS参数和所在时区:REM List NLS Parametersset linesize 90 pagesize 1400col Parameter for a40col Value for a40SELECT Parameter, Value FROM NLS_DATABASE_PARAMETERS/SELECT P... 阅读全文

摘要：以下脚本可以用于列出数据库内的排序活跃性能信息并监控临时空间的使用:REM SORT ACTIVITYset linesize 150 pagesize 1400; SELECT d.tablespace_name "Name", TO_CHAR(NVL(a.bytes / 1024 / 1024, 0),'99,999,990.900') "Size (M)... 阅读全文

摘要：以下脚本用以列出数据库中对象的依赖性:REM OBJECT DEPENDENT select D_OBJ#, do.object_name, do.object_type dtyp, do.status dsta, D_TIMESTAMP, ORDER#, P_OBJ#, po.object_name,... 阅读全文

摘要：Below lists Oracle SQL Function , and which version introduce this:SQL> SELECT NAME,VERSION,DATATYPE,DESCR FROM v$sqlfn_metadata order by 2;NAME VERSION DATATYPE DESCR-... 阅读全文

摘要：Below lists Oracle SQL hints: Sql hints View more documents from Maclean Liu 阅读全文

摘要：该脚本可以用于列出Oracle日志文件切换的频率图:REM Log Switch Frequency Mapcol Day for a10col Date for a10set linesize 80SELECT trunc(first_time) "Date", to_char(first_time, 'Dy') "Day", count(1) "Total", ... 阅读全文

摘要：该脚本用以汇总表空间使用情况报告:REM tablespace reportset linesize 200select a.tablespace_name, round(a.bytes_alloc / 1024 / 1024) megs_alloc, round(nvl(b.bytes_free, 0) / 1024 / 1024) megs_free, ro... 阅读全文

摘要：以下脚本可以用于收集数据库安全风险评估信息:REM list database vulnerability assessment infoset escape on;set linesize 140 ;spool db_vulnerability_assessment.logSelect role from dba_roles r where role not in ('CONNECT', ... 阅读全文

摘要：Alert logfile reported as below:*********************Wed May 27 13:11:47 2009Errors in file /u01/app/oracle/admin/proa021/udump/proa021_ora_9533.trc:ORA-07445: exception encountered: core dump [memset... 阅读全文

摘要：Parameter cpu_count is determined by Oracle Software when instance started, But we can set it manually. This parameter can affect lots of hidden initialization parameters,see:SQL> select * from v$ver... 阅读全文

摘要：一套HP-UX Itanium平台上的10.2.0.2，实例意外终止，维护人员尝试重启实例，在数据库打开后数秒，smon后台进程报ORA-00600: internal error code, arguments: [kddummy_blkchk], [120], [856039], [6110]错误，实例再次意外终止。部分告警日志如下:Corrupt Block FoundTSN = 50, T... 阅读全文

摘要：SQL> select count(*) from WWork;COUNT(*)----------116114select count(*) from WWork where Work_WorkID = 100;select count(*) from WWork where Work_WorkID = 100*ERROR at line 1:ORA-00600: internal error ... 阅读全文