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datafile on nfs mount
Q:Per note 359515.1 nfs mounts are supported for datafiles with oracle 10. Does anyone know if the same applies for 9.2 databases? I urgently need to create a clone of a 9.2 environment, but suprise s...
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备份文件的管理(rman,find,gzip etc.)
My Unix Rman scrīpt runs Rman that puts the backups in a certaindirectory. I use the find command to compress all files that have notalready been compressed. (find $BACKUP_DIR/* \! -name '*.gz'...
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linux制作安装包的两种方法
制作安装包的两种方法：减法:在现有suse 母盘的基础上,对所有软件包进行一一挑选,把不要用的包挑出来,一一减掉.感觉这种方法难于达到最小,需要较多时间. 加法:重新安装一个最小的 suse 操作系统,再把大家...
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awk拼sql时要注意分号，单引号的问题.
以TAB分隔三列第1列： 分表编号 (str)第2列： id (bigint)第3列：title (varchar)要求将分表中对应id的title改为新的title值example: update tablename_nnn set title='很亮吧#%%%' where id=338542209638673 ...
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mysql支持gbk(zt)
http://bbs.chinaunix.net/viewthread.php?tid=8654921) configure的时候可以，有个扩展的字符集可以选2) 二进制安装(rmp) set names gbk3) 修改my.cnf default-character-set=gbk 4) 改conf...
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linux c程序内存检查器
http://blog.sina.com.cn/s/blog_5902731a0100af71.htmlhttp://dev.mysql.com/doc/refman/5.0/en/tools-used-to-create-mysql.htmlJulian Seward Author of valgrind, an excellent memory checker tool that ha...
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apache动态编译/静态编译区别
http://space.itpub.net/16555225/viewspace-495942以前编译apache的时候都是google搜索到的直接拿来用这次自己编译mod_rewrite和ssl遇到了问题又不知道问题出在哪里一个是mod_rewrite模块没有起作用一个是以ssl启...
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ocm考试
http://hi.baidu.com/oracle_10g/blog/item/7b0b0e4fe7bb7335afc3abdb.html不是很详细,比如报名,培训安排,课程内容,考式内容等等都没提到; 是讲9i的ocm,10g不知收费与老试内容是否有变化可以抽点时间到hk考一下.[@more@]m
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tempfile空间分配的时机--访问块时
When you create or resize tempfiles, they are not always guaranteed allocationof disk space for the file size specified. On certain file systems (for example,UNIX) disk blocks are allocated not at file creation or resizing, but before theblocks are accessed.Caution: This enables fast tempfile creation and resizing;however, the disk could run of space later when the tempfiles areaccessed.在创建或resize后，接下来做一个大的排序操作，让空间得到分配，这样真正到了用的时候就不会花时间在allocate上了. 并
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块空间释放与压缩
Delete, update两类语句可以增加block中的free space释放的空间在下面的条件下可以被随后的insert使用1) insert与释放空间的delete/update在同一个事务中,insert在后2) insert与delete/update在不同事务中, 只有当delete/update所在事务提交后，insert才能使用释放的空间block中释放的空间可能不连续, oracle在下面两个条件满足时会愈合块中碎片1) update/insert语句尝试使用这个块在存储 a new row piece，而这个块包含有足够的free space(算上连续空间与碎片空间)2) 因为不连续,这个new row piece无法insert进来这种做的原因是为了性能考
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Free Space Management中assm相对于manual的优点
Free space can be managed automatically or manually.Free space can be managed automatically inside database segments. The in-segment free/used space is tracked using bitmaps, as opposed to free lists. Automatic segment-space management offers the following benefits:.Ease of useBetter space utilization, especially for the objects with highly varying row sizesBetter run-time adjustment to variations in concurrent accessBetter multi-instance behavior in terms of performance/space utilizationYou spe
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concepts中关于block分配时机的说明
Although you can allocate additional extents, the blocks themselves are allocated separately. If you allocate an extent to a specific instance, the blocks are immediately allocated to the free list. However, if the extent is not allocated to a specific instance, then the blocks themselves are allocated only when the high water mark moves. The high water mark is the boundary between used and unused space in a segment.分配extent时,blocks不是马上分配,分成两种情况:1, 如果extent分配到具体的instance(r
