Oracle OCP 052 Exam Learning

1. The data dictionary is stored in the system table space.

2.SYSAUX can be offline:

Sql>alter tablespace sysaux offline;

Both 3.SYSTEM and Sysaux are permanent table spaces and cannot be used for temporary table spaces.

Neither 4.SYSTEM nor Sysaux can be read-only mode.

5.fast_start_mttr_target: is a parameter that accelerates instance recovery.

The value is in seconds, such as set to 60s, assuming that the value is in a reasonable situation, then an instance crashes, it should be restored within 60s;

Reasonable meaning is not too big, nor too small,

Too large to allow the recovery time to be too long,

Too small can result in an instant write of large amounts of data, resulting in excessive system I/O stress.

In the case of a value of 0 for Fast_start_mttr_target, the official document says,

Explicit setting of the Fast_start_mttr_target parameter to 0 disables automatic checkpoint tuning. Explicit setting of the Fast_start_mttr_target parameter to a value other than 0 also enables the Redo Log Advisor.

Setting the value to 0 disables automatic checkpoint tuning, which is greater than 0 o'clock and also supports redo log suggestions.

It can be used not only under Archivelog, but also under Noarchivelog.

6.external Tables External table:

In short, an external table is a table that does not exist in the database, and similarly, we can consider an operating system file as a read-only database table;

External data tables are read-only, so DML operations cannot be used and indexes cannot be created;

The Analyze statement does not support the analysis of statistics for external tables, and the Dmbs_stats package should be used to collect external table operations;

The database only holds the description of the table structure, and the table data is not stored in the database but stored on the file system;

The external table of resumes does not produce storage structures such as regions, segments, and data blocks.

7.DBCA cannot be used to upgrade a database.

8. Data pump IMPDP only binary files generated by EXPDP can be imported.

9.role can be protected by a password.

10.role The role can be created as long as the permissions given to create role.

11.bigfile tablespace can contain only a single data file and cannot span multiple data files.

The 12.permanent tablespace permanent tablespace can contain (contain) multiple data files instead of spanning (span) multiple data files.

13.temporary tablespace temporary tablespace contains temporary files instead of data file.

14.extents can only be a data file.

15. In Undo auto-management, after setting the Undo_retention, the undo block has four states:

Active: Indicates that the undo that is being used is not committed or has not been rolled back.

Inactive: Indicates that there are no active transactions on this undo, and the undo of that state can be overridden by other transactions.

Expired: Indicates that the undo has lasted inactive longer than the time specified by Undo_retention.

Freed: Indicates that the undo block has not been used and is empty.

A 16.undo table space can include multiple data files.

17.sigle-instance databases can has only one active undo tablespace.

18. Only when the tablespace is set to Gurantee can you ensure that the committed data is persisted and the time that the Undo_rentention parameter is set.

The 19.UNDO tablespace is only used for undo segments (You cannot create other types in the undo tablespace, such as tables, indexes, and so on) and can only be associated with a single instance.

The Pmon of the 20.oracle process:

Processmonitor Process Monitoring

Data recovery occurs when a user process is not properly interrupted.

The Pmon is responsible for cleaning up the data buffer pool and freeing the resources used by the user process, such as uncommitted transactions, releasing locks, and removing dead processes in the process column.

The reco of the 21.oracle process:

reco:recovererprocess recovery process

This process is a process that will be used in distributed options and will automatically resolve failures in distributed transactions.

The ARCN of the 22.oracle process:

Arcn:archiverprocess Archive Process

ARCN will replicate the redo log file to the specified storage device after the log exchange occurs.

ARCN occurs if: 1. The database must be an archive mode. 2. The database must be automatically archived.

23.Automatic Diagnostic Repository (ADR):

It is a file-based repository for storing database diagnostic information such as traces, dumps, alert log, and health monitoring reports.

databases, automated storage management (ASM), Cluster readiness Services (CRS), and other Oracle product components store all diagnostic data in ADR, and different products and components have the same directory structure.

The database initial parameter diagnostic_dest determines where the ADR BASE is stored, by default, if Oracle_base is set, then Diagnostic_dest equals oracle_base, otherwise equals oracle_home/ Log A parameter diagnostic_dest is specified, and the position set by the original parameters core_dump_dest, Background_dump_dest, and User_dump_dest is ignored.

24.SGA: System Global Zone

Included components: Shared pool, database buffer cache, log buffer cache, large pool, Java pool, stream pool, and so on.

25.db_create_file_dest

Setting the Db_create_file_dest initialization parameter sets the default path for the file: datafiles, tempfiles, redo log files, control files, block change tracking files.

26.SQL Access Advisor: Provides recommendations for materialized views, indexes, partitions, and more.

SQL Tuning Advisor: can provide materialized views, indexes, partitions and other suggestions; run automatically in the Maintenance window.

Small difference: SQL Tuning advisor adjusts each SQL statement individually; SQL Access Advisor adjusts all SQL statements at the same time.

27.Database Configuration Assistant: In the Nomount State, only the service is deleted and the data is not deleted.

28.Automatic Workload reporsitory (AWR): Automated Workload repository

The data collected and processed by AWR include: Object statistics, time model statistics, system and session statistics, and session history statistics.

AWR is enabled by default. The parameters are controlled by the Statistics_level initialization (parameters include all, typical, BASIC), which defaults to typical,

Typical and all will enable AWR statistics collection by default, and basic disables many Oracle database features, including AWR, but can still manually capture AWR statistics via dbms_workload_repository.

By default, a snapshot is generated every hour and eight days of load statistics are retained.

The AWR information is saved in the Sysaux table space.

Oracle OCP 052 Exam Learning