摘要： Defines the attributes of a Transact-SQL server cursor, such as its scrolling behavior and the query used to build the result set on which the cursor ... 阅读全文

摘要： 1、查看数据库锁,诊断锁的来源及类型： select object_id,session_id,locked_mode from v$locked_object;或者用以下命令：select b.owner,b.object_name,l.session_id,l.locked_modefrom v... 阅读全文

摘要： The Transact-SQL programming language provides several SET statements that change the current session handling of specific information. The SET statem... 阅读全文

摘要： Temporary tables are created in tempdb. The name "temporary" is slightly misleading, for even though the tables are instantiated in tempdb and backed ... 阅读全文

摘要： question:if the nested transaction encountered an exception, then rollbacked. How about the outer transaction?Lets demo this using below code.create p... 阅读全文

摘要： fromhttp://www.akadia.com/services/ora_chained_rows.htmlOverviewIf you notice poor performance in your Oracle database Row Chaining and Migration may ... 阅读全文

摘要： ITpub 上有个帖子 http://www.itpub.net/thread-1852068-1-1.html生产数据库版本10.2.0.4测试数据库版本10.2.0.1sql在生产库运行就使用了谓词推进，效率很高，只要3s，但是在测试库没有使用谓词推进，需要6分30s。大家帮忙看看如何优化或者强... 阅读全文

摘要： SQL> drop table test;表已删除。SQL> create table test as select * from dba_objects where 1!=1;表已创建。SQL> create index idx_test_id on test(object_id);索引已创建。S... 阅读全文

摘要： 还原DUMP出来的数字SQL> select dump(2000,16) from dual;DUMP(2000,16)------------------Typ=2 Len=2: c2,15SQL> declare n number; 2 begin 3 dbms_stats.convert_ra... 阅读全文

摘要： 一.Memory Dumps1).Global AreaALTER SESSION SET EVENTS 'immediate trace name global_area level n';1 包含PGA2 包含SGA4 包含UGA8 包含indrect memory2).Library Cach... 阅读全文