Shulou(Shulou.com)06/02 Report--

Blog structure

Configure and connect to the database

Control the management of documents

Management of log files

Management of archived logs

Data dictionary

one。 Configuration database

In the actual production environment, Oracle is generally managed and maintained remotely. Besides the use of client tools, the communication principle of Oracle remote operation also needs to be mastered.

Oracle client side and server side

Whether you use SQL*Plus tools or third-party tools to connect to a remote database, you must establish both the client and server side

The connection between them. Oracle provides Oracle Net Services components for easily configuring and managing network connections. These components are not

It needs to be installed separately and will be installed automatically when you install Oracle server or client software.

Enable listening [oracle@Oracle ~] $lsnrctl start

1.Oracle Net protocol

As shown in the figure, Oracle realizes the connection and data transmission between client and server through Oracle Net protocol. Oracle Net

Is a software layer that resides on both the Oracle server and the client. It encapsulates the TCP/IP protocol and is responsible for establishing and maintaining customers.

Connection of the client application to the database server.

two。 The connection process between the client and the server

Before analyzing the connection mechanism between the client and the server, you need to understand two concepts: one is the Oracle Net listener and the other is the Oracle network service name.

Case: client remote connection oracle

[root@oracle ~] # systemctl stop firewalld [root@oracle ~] # vim / etc/sysconfig/network-scripts/ifcfg-ens33 [root@oracle ~] # systemctl restart network [root@oracle ~] # xhost + access control disabled, clients can connect from any host [root@oracle ~] # su-oracle [oracle@oracle root] $export DISPLAY=:0.0 [oracle@oracle ~] $lsnrctl start [oracle@oracle ~] $sqlplus / as sysdbaSQL > select instance_name from v$instance [oracle@oracle admin] $pwd/u01/app/oracle/product/12.2.0/dbhome_1/network/ admin [oracle @ oracle admin] $vim tnsnames.ora\\ gaiyi change the address

The client configuration is as follows:

Download oracle client software

Default is always the next step.

Click to edit the file

The configuration is as follows

ORCL = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP) (HOST = 192.168.1.1) (PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SID=orcl)

Save

Open the connection

two。 Management control file

The control file plays a very important role in the Oracle database. If the control file is damaged or lost, the database can not be started, so it is very important for DBA to manage and maintain the control file reasonably.

The role of control files in database startup

For DBA, Oracle database control file is a very important file. It is a binary file automatically generated when the database is created, which records the status information of the database and mainly includes the following:

The name of the database, a control file can only belong to one database. The time when the database was created. Name, location, online and offline status information of the data file. The name, location, and archive information of the redo log file. All tablespace information. The current log serial number. Recent checkpoint information.

The control file is read during the MOUNT phase of database startup. The relationship between database startup and control files is shown in.

Case: backup and restore database

Get control file information SQL > select name from v$controlfile NAME----/u01/app/oracle/oradata/orcl/control01.ctl/u01/app/oracle/oradata/orcl/control02.ctlSQL > get the contents contained in the control file

SQL > select type,record_size,records_total,records_used from v$controlfile_record_section

Create a multiplexing control file [oracle@rhel1 ~] $su-root [root@oracle ~] # mkdir-p / backup1/control [root@oracle ~] # mkdir-p / backup2/control [root@oracle ~] # chown-R oracle / backup1 [root@oracle ~] # chown-R oracle / backup2 while the database is still open Modify the contro_files parameter SQL > alter system set 2 control_files= 3'/ u01 in spfile The system has changed.

Shut down the database

SQL > shutdown immediate

Use operating system commands to copy files to a new location

SQL > quit; [oracle@rhel1 ~] $cp / u01/app/oracle/oradata/orcl/control01.ctl / backup1/control/control02.ctl [oracle@rhel1 ~] $cp / u01/app/oracle/oradata/orcl/control01.ctl / backup2/control/control03.ctl

Restart the database

[oracle@rhel1 ~] $sqlplus sys/123456 as sysdba

SQL > startup

4. Backup and recovery control files

Directly overwrite damaged or missing control files with existing intact control files

Simulate failure, stop database, delete control file

Sql > shutdown immediatesql > quit$rm-f / badkup1/control/control02.ctl

Start the database

Sql > startup observation phenomenon

Restore control file

Sql > shutdown abort;sql > quit$ cp / u01/app/oracle/oradata/orcl/control01.ctl / backup1/control/control02.ctl

Start the database again

Sql > startup

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