按类别查询搜索结果
关于关键词 的检测结果,共 3339
unix_5359 | 2019-11-04 10:49:06 | 阅读(680) | 评论(0)
Which two statements are true about transactions in the Oracle Database serve?B) Data Manipulation Language (DML) statements always start a new transaction.D) A Data Detiniton Language (DDL) statement does a commit automatially only for the data dictionary updates caused by the DDLF) I...【阅读全文】
unix_5359 | 2019-11-04 10:18:09 | 阅读(860) | 评论(0)
In the PROMOTIONS table, the PROMO_BEGTN_DATE columm is of datatype DATE and the default date format is DD-MON-RR.A) TO_NUMBER(PROMO_ BEGIN_DATE) - 5 will return numberC) PROMO_BEGIN_DATE - SYSDATE will return a number.E) PROMO_BEGIN_DATE - SYSDATE will return an error.(解析:这道...【阅读全文】
unix_5359 | 2019-10-25 14:59:53 | 阅读(900) | 评论(0)
Examine this partial command:cust_id NUMBER(2),)Which two clauses are required for this command to execute successfully?B) the REJECT LIMIT clauseD) the ACCESS PARAMETERS clauseAnswer:AD【阅读全文】
unix_5359 | 2019-10-25 14:13:42 | 阅读(770) | 评论(0)
Examine the description of the PRODUCTS table:-----------------------------------------------------------------PRODUCT_NANE                     VARCHAR2(10)PURCHARGE                  &nb...【阅读全文】
unix_5359 | 2019-10-21 11:39:52 | 阅读(850) | 评论(0)
Which three statements are true about dropping and unused columns in an Oracle database?B) A DROP COLUMN command can be rolled backD) An UNUSED column's space is redaimed automatially when the row containing that column is next queried.F) A column that is set to NNUSED still counts tow...【阅读全文】
unix_5359 | 2019-10-21 10:25:04 | 阅读(650) | 评论(0)
Which two statements are true about a self join?B) It can be a left outer join.D) It can be an inner join.Answer:BD不过在进行内连接时为了区别表的名字,需要加别名from emp2 won w.mgr=m.empno;)【阅读全文】
unix_5359 | 2019-10-18 14:51:08 | 阅读(1050) | 评论(0)
Which two statements are true about Oracle synonyms?B) All private synonym names must be unique in the database.D) A synonym can be created on an object in a package.(解析:同义词也是 Oracle 的一个对象;【阅读全文】
unix_5359 | 2019-10-18 09:36:29 | 阅读(660) | 评论(0)
Which three statements are true about views in an Orade batabase?B) Rows inserted into a table using a view are retained in the table if the view is doppedD) Views have no segment.F) A view can be created that refers to a non-existent table in its defining query.(解析:...【阅读全文】
unix_5359 | 2019-10-17 11:49:07 | 阅读(630) | 评论(0)
The EMPLOYEES table contains columns EMP_ID of data type NUMBER and HIRE_DATE of data type DATEThe NLS_TERRITORY parameter is set to AMERICA in the session and, therefore, Sunday is the first day ofthe weekA) SELECT emp_id,NEXT_DAY(ADD_MONTHS(hite_date,6), 'MONDAY') FROM employees;C) S...【阅读全文】
unix_5359 | 2019-10-17 09:52:27 | 阅读(620) | 评论(0)
Which three are true about granting object privileges on tables, views, and sequences?B) DELETE can be granted on tables, views, and sequences.D) INSERT can be granted on tables, vews, and sequences.F) ALTER can be granted only on tables and sequences.(解析:update 和 delete 只能在...【阅读全文】
unix_5359 | 2019-10-15 10:03:24 | 阅读(640) | 评论(0)
Exammine the desciption of the PRODUCT DETALS table:--------------------------------------------------PRODUCT_NAME  NOT NULL  VARCHAR2(25)EXPIRY_DATE  DATEA) PRODUCT_ID can be assigned the PEIMARY KEY constraint.C) EXPIRY_DATE contains the SYSDATE by defalt if no...【阅读全文】
Frank_China | 2019-10-09 09:14:39 | 阅读(4980) | 评论(0)
Frank_China | 2019-09-19 16:13:16 | 阅读(7920) | 评论(0)
  select * from v$log;  select * from v$logfile;  alter system switch logfile;  select * from v$log_history;  select dbid,name,created,log_mode from v$database;  select recid,stamp,thread#,sequence#,name from v$archived_log;  alter database add logfile group 1...【阅读全文】
Frank_China | 2019-09-19 16:09:58 | 阅读(1960) | 评论(0)
查看日志文件组状态信息 select group#,status from v$log; inactive:非活动状态 current:当前正在被使用 active:活动的非当前日志,该日志可能已经完成归档,也可能没有归档,活动的日志文件在crash恢复时会被用到 unused:日志从未被使用 上图表名数据库正在使用日志文件组3...【阅读全文】
dbwatcher | 2019-09-03 09:30:54 | 阅读(8220) | 评论(0)
博客文章除注明转载外,均为原创。转载请注明出处。ogg状态发现延迟:GGSCI (ceshi) 4> info allProgram     Status      Group       Lag at Chkpt  Time Since ChkptMANAGER     RUNNING             ...【阅读全文】
dbwatcher | 2019-07-15 16:37:43 | 阅读(6900) | 评论(1)
博客文章除注明转载外,均为原创。转载请注明出处。count(*)对行的所有数目进行计算,包含NULL值的行。count(column)对特定的列的值具有的行数进行计算,不包含NULL值的行。count(1)的结果和count(*)的结果是一样的。小例子:sys@orcl-192.168.0.21> select count(*) from v$session;  COUNT(*)----------&...【阅读全文】
evan_china | 2019-06-05 10:00:37 | 阅读(1060) | 评论(0)
通过以下SQL可以获取每个时间段DB Time的使用情况,进而了解业务系统的高峰时段。SELECT inst_id,       SNAP_END_TIME AS SNAP_TIME,       HOURMIN,       ROUND((VALUE - LAST_VALUE) / 1000000 / 60, 2) DB_TIME,       ROUND(R...【阅读全文】
法典化健 | 2019-06-03 14:13:43 | 阅读(600) | 评论(0)
同时也再次感受到良好的基础是深入学习的前提。特别强调本文档仅用于学习,并非是要修改redis源码。 建议读者阅读本文档时实际动手敲一下代码,然后翻阅下redis源码,debug下redis本文档分为三大部分:实现命令redis原生命令命令含义...【阅读全文】
hxl | 2019-02-28 16:17:41 | 阅读(19000) | 评论(0)
------------------方法1在主库上使用备份的进行恢复丢失的归档日志------------------------------1.发现主库备份后删除了归档,但是这些归档从库还没应用,也没有传到从库从库应用的最新的归档日志为592SQL> connect / as sysdbaConnected.SQL> Select Max(t.SEQUENCE#) From V$archived_Log t;MAX(T.SEQUENCE#)--...【阅读全文】
liyf0371 | 2019-02-13 11:40:44 | 阅读(1480) | 评论(0)
--//使用reuse storage选项,存储空间不会回收,另外在truncate时,数据段号data_object_id会发生变化,自己想想是否 --//可以通过修改相应数据库的段号指向新的段号来实现恢复.自己动手测试看看.create table empx as select * from emp;SCOTT@book> @ rowid AAAWFOAAEAAAALbAAA     OBJ...【阅读全文】