MySQL 体系结构以及各种文件类型学习汇总
1,mysql体系结构由数据库和数据库实例组成,是单进场多线程架构。数据库:物理操作系统文件或者其它文件的集合,在mysql中,数据库文件可以是frm、myd、myi、ibd等结尾的文件,当使用ndb存储引擎时候,不是os文件,是存放于内存中的文件。数据库实例:由数据库后台进程/线程以及一个共享内存区组成,共享内...
ORACLE体系结构小结
1. Oracle数据库中的数据库与实例Oracle数据库包括一个数据库和至少一个实例(通常是指只有一个实例),数据库和实例是紧密相关的,Oracle数据库这个术语有时即指实例,也指数据库。这个术语严格的意义具有以下的含义:数据库数据...
数据库控制文件中的SCN详解
在的启动和关闭数据库的时候控制文件起着重要的作用,从官方文档中我们可以知道控制 文件中保存着下列的信息:数据库的名称及数据库创建时...
Oracle中的联机日志文件发生不同程度损坏的恢
ORACLE通过redo来保证数据的重演,从而使得在数据库故障的时候,可以恢复,在数据库中redo文件至关重要。?????????1.对于联机日志损坏要根据日志状态进行分析,联机日志一般分为Current Active Inactive和unused四种状态,unused日志组还没有使用。Inactive状态的日志不会造成数据的丢失,而Acti...
OCP-IZO-053_QUESTION614
QUESTION NO: 614 Which three types of files can be automatically placed in the flash recovery area (fast recovery area in 11g Release 2)?(Choose three.)A. Alert ...
OCP-IZO-053_QUESTION395
QUESTION NO: 395Which of these formats represents the correct hierarchy for the ADR?A. <diagnostic_dest>/rdbms/diag/<dbname>/<instname>B.<diagnostic_dest>/diag/rdbms/<instname>/<dbname> C. <diagnostic_dest>/...
OCP-IZO-053_QUESTION394
QUESTION NO: 394 Which of the following statements is true regarding the initialization parameter DIAGNOSTIC_DEST? A. The default value is the value of the&nbs...
OCP-IZO-053_QUESTION387
QUESTION NO: 387Which method could be utilized to identify both DML operations and the SQL statements needed to undo those operations for a specific schema owner? (...
OCP-IZO-053_QUESTION385
QUESTION NO: 385 Which of the following statements is true regarding implementing a Flashback Table recovery? A. An SCN is never used to perform a Flashback&nb...
OCP-IZO-053_QUESTION384
QUESTION NO: 384Which of the following statements is true regarding the VERSIONS BETWEEN clause? A. The VERSIONS BETWEEN clause may be used in DML statements.B. ...
OCP-IZO-053_QUESTION382
QUESTION NO: 382 Which of the following can be used in conjunction with a Flashback Versions Query to filter the results? (Choose all that apply.)A. A range&nbs...
OCP-IZO-053_QUESTION381
QUESTION NO: 381 Which pseudocolumn could you use to identify a unique row in a Flashback Versions Query? A. XIDB. VERSIONS_PKC. VERSIONS_XIDD. VERSIONS_UNIQUE ...
OCP-IZO-053_QUESTION380
QUESTION NO: 380Which of the following statements best describes Flashback Versions Query?A. Flashback Versions Query is used to make changes to multiple versions of data...
OCP-IZO-053_QUESTION375
QUESTION NO:375 Over the course of a day, a department performed multiple DML statements (inserts, updates, deletes) on multiple rows of data in multiple tables. The&nbs...
OCP-IZO-053_QUESTION373
QUESTION NO: 373 Which of the following Oracle features utilize the undo tablespace? (Choose all that apply) A. Flashback QueryB. Flashback DropC. Flashback TableD...
OCP-IZO-053_QUESTION360
QUESTION NO: 360 When performing a full database disaster recovery with RMAN, in what order would you execute these steps?A. Restore the control file from auto...
OCP-IZO-053_QUESTION353
QUESTION NO: 353True or false: tablespace point-in-time recovery is possible only with RMAN. A. TrueB. False 【题目示意】此题考查有关于recover tablespace的相关知识。【解析】 &n...
OCP-IZO-053_QUESTION352
QUESTION NO: 352 If a backup is expired, which of the following is true? A. It can never be used for a restore/recover operation.B. Oracle will re...
OCP-IZO-053_QUESTION351
QUESTION NO: 351 What information does the report schema command not provide? (Choose all that apply.) A. Size of the datafiles B. Size of the tempfiles C. Date o...
OCP-IZO-053QUESTION349
QUESTION NO: 349 What is the result of this command? RMAN> Report need backup days 3; A. Lists all datafiles created in the last three days that ar...