Database Administrator

The problem in the previous log "Oracle clause group by cube" (SEE) is slightly changed. Now each field has three states. How can I write SQL statements? At this time, the CUBE mechanism may not be able to form 3 of the eight power line data, you

Today I received a strange fault and found that some packets are running normally on NODE1, and then the execution on NODE2 reported a ORA-04068 error. however, check whether the STATUS of DBA_INVALIED_OBJECTS is normal. (because some packages in

I. node information:Master1: 192.168.80.143/24 + CAMaster2: 192.168.80.144/24 The two nodes are the same as the master node and the slave of the other node. Ii. Basic Configuration: (1) mysql is installed on both servers. # pvcreate /dev/sda5   

ADADMIN usage ADADMIN is used to maintain the Oracle Apps file system and database. It is a common tool for Apps DBAs. (The ADADMIN execution file is located under $ AD_TOP/bin) Usage Oracle@www.bkjia.com ~ $Adadmin If the ADADMIN command cannot be

Set on the click node or Local Machine 1 SQL> archive log list; # Check whether archive mode is used 2 SQL> alter system set log_archive_start = true scope = spfile; # enable automatic archiving SQL> alter system set log_archive_dest_1 = 'location =

Today, I upgraded MySQL from 5.1.26-rc to 5.5.15. The source code packages downloaded from the official website are compiled. MySQL 5.5.15 is provided by my colleagues. Because the existing database uses the innodb engine, mysqldump is used to

In daily O & M, DDL operations on production data tables must be taken with caution. O & M DBAs generally consider data DDL operations globally, such as impact on production, execution duration, and impact on storage data. Adding the default values

In the previous article, Understanding the basic concepts of redo log (1) Media recovery and instance recoveryUnderstanding redo (2) redo content: change vector and redo entriesUnderstanding redo (3) explain an update processUnderstanding redo (4)

Wildcard description _ Match with any single character % Matches a string that contains one or more characters. [] Matches any single character in a specific range (for example, [a-f]) or a specific set (for example, [abcdef. [^] Matches any

After the system executes expdp export, alert. log reports the service name modification information, as follows: Wed Sep 05 02:09:29 2012Alter system set service_names = 'sys $ SYS. KUPC $ C_1_20120905020929.ZZBRAC3 'SCOPE = memory sid = 'zzbrac31 '

In Oracle, commands and object names are case-insensitive, because Oracle converts all the names and commands into uppercase when processing statements.However, the characters in a string, whether compared or sorted, are case sensitive. This is the

OracleDatabase Log status We queryV $ logThe view shows the log status. SQL> select group #, ARCHIVED, status fromv $ log;  GROUP # ARC STATUS ----------------------------- 1 NO CURRENT 2 YESINACTIVE 3 YES ACTIVE   CurrentIndicates the currently

In Oracle databases, the three major files (Data File, Control File, and Online Redo Log) play an extremely important role. The Redo Log and Oracle Redo Log mechanisms guarantee normal and safe operation of Oracle. Oracle Online Redo Log adopts the

Srvctl is a command line tool provided by Oracle to manage the RAC environment of Oracle. Srvctl is introduced in Oracle 9i. Oracle10g and 11g greatly improve its functions. The following describes the simple usage of this command. 1. view the

Cause: The union all operation is required in the query, and the operation cannot be completed because the LONG type field exists in the table. Modify the LONG type field to the CLOB type according to the specific business scenario. After the

When Oracle 11gR2 11.2.0.2 RAC is installed on Linux today, the following error is reported. By querying the log file content, the following prompt is displayed: INFO:   11rac2,11rac1 

A single-instance database generally has the database name db_name, Instance name: instance_name: Service name: service_names. Generally, the three names are consistent. There are some differences in the RAC cluster. In terms of planning, we will

Usually, data storage needs to specify the case sensitivity of string fields. MySQL Default queries are not case sensitive. However, as user information, once the user name is repeated, it will waste a lot of resources. In addition, it is difficult

MySQL 5.0.37 and later versions support PROFILING debugging, allowing you to learn more about resource consumption of SQL statements. Because it needs to call the system's getrusage () function, it can only be used on Linux/Unix platforms, rather

ORA-00257 archiver error -- archiving failed due to full data flash back System: Windows Server 2008 R2 Database Version: Oracle 10.2.0.4 This morning, an error occurred at work: ORA-00257: archiver error. Connect internal only, until