2013-06-10 ONE PASS AND MULTI PASS
http://blog.163.com/dazuiba_008/blog/static/36334981201162915350492/ONE PASS AND MULTI PASS 2011-08-01 14:59:27|&nbs...
2013-05-15 EXPDP/IMPDP任务的查看与管理
http://blog.chinaunix.net/uid-74941-id-161059.htmlEXPDP/IMPDP相比传统的exp/imp的最本质区别在于服务器端执行,客户端发出指定后,通过API启动服务器的备份job,在执行过程中,可以拿下Ctrl+C组合键,退出当...
2013-05-09 Partition-Wise Join of List-Partitioned Tables
http://www.antognini.ch/2010/08/partition-wise-join-of-list-partitioned-tables/Partition-Wise Join of List-Partitioned Tables Aug022010 ...
2013-04-08 lob pre-fetching
http://yumianfeilong.com/html/2013/03/24/601.htmlLobPrefetch: Faster Lob fetching in a single roundtripMarch 24th, 2013 | Categories: Boring | Tags: JDBC, Lob, Oracle...
2013-03-14 System-generated names formats
System-generated names default to these formats:SYS_LOB(10 digit object_id)C(5 digit col#)$$SYS_IL(10 digit object_id)C(5 digit col#)$$
2013-02-05 Parse CPU to Parse Elapsed%
http://www.askmaclean.com/archives/know-more-about-awr-parse-statistics.htmlhttp://www.itpub.net/thread-1762903-1-1.htmlhttp://t.askmaclean.com/thread-1113-1-1.htmlParse CPU to Parse Elapsed%是一个我...
2013-02-01 SESSION_CACHED_CURSOR & BIND VARIABLE GRADUATION
SESSION_CACHED_CURSOR:当设定SESSION_CACHED_CURSOR的值之后,当有parse请求的时候,Oracle会从library cache中查询。如果有超过3次同样的parse请求,这个游标将会存入Session的游标缓存中。对于将来同样的查...
2013-01-31 deleted index entries
索引块只有当全部数据被删除后才能被新的不同值数据插入否则只有插入相同的值的时候才能利用原来删除的空间但是这里呢,要说明一点的是:记录删除的时候索引并没有被真正地从物理上删除,仅仅是在该索引叶子...
2012-12-05 generate sequence
--1. by japanselect level n from dual connect by level <=10;--2. by tomkyteselect rownum n from all_objects where rownum<=10;--3. select to_number(column_value) n from xmltable('1 to 10');...
2012-11-30 IGNORE_ROW_ON_DUPKEY_INDEX
http://yangtingkun.itpub.net/post/468/492003在11.2中,Oracle新增了一个HINT,使得INSERT INTO SELECT操作可以避免插入重复的记录。首先创建一个包含主键的表:SQL> CREATE TABLE T 2 (ID NUMBER, 3 NA...
2012-09-26 PLAN HASH VALUE ISSUE ABOUT SUBQUERY FACTORING
with subq as ( select /*+ materialize */ outer.* from &...
2012-09-26 APPEND_VALUES Hint
APPEND_VALUES Hint in Oracle Database 11g Release 2http://www.oracle-base.com/articles/11g/append-values-hint-11gr2.phpWe have been able take advantage of the performance benefits of direct-pat...
2012-08-28 ROWDEPENDENCIES
http://www.itpub.net/thread-982860-1-1.html默认表中修改块中的记录会影响本块其他记录的 ora_rowscn如果加上ROWDEPENDENCIES ,那么修改记录只影响本记录的ora_rowscn,不会引起其他记录的改变加上这个功能,会...
2012-08-17 New Implementation for Nested Loop Joins
http://docs.oracle.com/cd/E11882 ... optimops.htm#i49732Oracle Database 11g introduces a new implementation for nested loop joins to reduce overall latency for physical I/O. When an index or a table...
2012-07-19 issue: drop materialized view log
http://www.itpub.net/thread-1637386-1-1.html在表AAA上创建了物化试图,但用户通过drop table MLOG$_AAA的方式把mview log直接干掉了,而不是通过 drop materialized view log on AAA的方式。此时再对这个表进行...
2012-07-19 Using Multicolumn Partitioning Keys
http://www.itpub.net/thread-1637063-1-1.htmlSQL> create table test 2 ( 3 a number, 4 b number, 5 c nu...
2012-07-19 ORA-1652: unable to extend temp segment
http://www.itpub.net/thread-1144914-1-1.htmlQ:数据表空间报ORA-1652: unable to extend temp segment by 8 in tablespace ...报的表空间不是临时表空间,是数据表空间用户也没有把此数据表空间用做临时表空间...
2012-03-07 递归wih
今天用递归with搞定一个sql,用connect by 弄了半天都没弄出来ref: http://www.itpub.net/thread-1225621-2-2.htmlWITH子查询也称为CTE (Common Table Expression),是ANSI SQL-99标准的一部分。ORACLE从9i开始...
2012-03-05 ArraySize
arraysize定义了一次返回到客户端的行数,当扫描了arraysize 行后,停止扫描,返回数据,然后继续扫描。 这个过程就是...
2012-02-22 Deferred Statistics Publishing
http://space.itpub.net/12020513/viewspace-62658411g的一个新特性,表示收集完统计信息不是立即发布(默认立即发布),让所有用户可用,而是可以先保存成待定统计信息,供测试用,当觉得测试结果满意,可靠后...