Database Administrator

When installing small patches in the RAC environment, you can use Rolling installation to provide uninterrupted business applications! When installing the patch, stop a database instance, install the patch on this node, start the instance, stop

1. Environment: CentOS5.5 x84, MySQL5.5.152. Two machines: master1: 192.168.5.143master2: 192.168.0.1493. Compile and install MySQL separately and test the connection.4. Create a user on both machines and grant the copy permission: master1: Mysql>

You need to perform data analysis between different records on the Oracle query results. You can find a syntax similar to a programming language on the Internet. DECLARE// Declare VariablesBEGIN// Specific operationIf then//..End if;Loop//..End Loop;

1. First, install the package mysql-5.1.28-rc.tar.gz for wget mysql, compile with configure before version 5.1, and compile with cmake for Versions later than version 5.1. Extract mysql-5.1.28-rc.tar.gz Tar-axvf mysql-5.1.28-rc.tar.gz 2. Enter the

Recently, you need to regularly back up Oracle databases in Ubuntu using cron. The specific steps are as follows: 1. Configure the environment variable/home/oracle/. profile for oracle users. # For oracleExport ORACLE_HOME =/opt/ora10Export ORACLE_

Error Code 1 in the slave log: [ERROR] Error reading packetFromServer: Client requested masterToStart replicationFromImpossible position;LastEvent wasRead From 'Mysql-bin.20.16' At455562731,LastByteReadWasRead From 'Mysql-bin.20.16' At4.

Cancel-based Inconsistency Recovery (archive) Article 1   Cancellation-based recovery only applies to the following situations: loss of archived logs leads to full recovery failure; loss of data files and Unarchived redo logs (online redo logs );  

In the Oracle world, you can use: 1) case expression or 2) decode Function To realize logical judgment. Oracle's DECODE function is very powerful. If you use it flexibly, you can avoid multiple scans to improve query performance. CASE is a syntax

MongoDBDataLibrary IntroductionMongoDB is a highPerformance,Open Source, NoneModeDocumentationDatabaseIt can be used in many scenarios to replace the traditional relational database or key/value storage mode. MongoDB uses C ++Development, Provides

1. Workspace Manager introduces Oracle Workspace Manager's architecture of creating different versions for different tables. Version Management (Workspace manager) is a new feature of Oracle 11g. It is embedded in the oracle database and allows

In the database design principle, the purpose of the Self-increasing field is to determine the uniqueness of each record for the unique index, and to ensure the query speed when the database volume is large. However, there are separate fields in

Oracle basic command: group by cube (Field List );The CUBE command generates different permutation and Combination Based on the field list, and generates statistical summary based on each combination result.For example: group by cube (city, job, age)

We often hear that in Oracle, when a role is granted user permissions, the user must log on again to obtain the permissions granted. How can this problem be solved? Let's take the following steps to understand the meaning of this sentence. 1. DBA

The MERGE statement is a new syntax of Oracle9i, used to merge update and INSERT statements. The MERGE statement is used to query another table based on the connection conditions of one table or subquery. The join condition matching is updated, and

Cause: In the RAC + RAW + ARCHIVE environment, several RAW files are added, but the host is modified on one side. The following error occurs: ORA-01157: cannot identify/lock data file 129-see DBWR trace file ORA-01110: data file 129:

Benefits of Compression Compression is an Oracle feature that is more suitable for Data Warehouse Environments. The benefits of compression include: 1. Saving storage space makes sense for massive data volumes. 2. the query performance will be

Raw Trace collection method 1. Open Trace, Help> Diagnostics> Trace with Binds and Waits. Meaning of the Trace item No Trace-turns trace off. Regular Trace-generates a regular SQL trace by executing the following statement: Alter session set

Question: known company employee table EMP (EID, ENAME, BDATE, SEX, CITY ), Department table DEPT (DID, DNAME, DCITY ), Worksheet WORK (EID, DID, STARTDATE, SALARY ). The fields are described as follows: EID-employee ID, which can contain a maximum

Content Introduction Document Collection Application Directory Information Application Document Classification Application XML search application Summary References Introduction Oracle full-text search allows you to create text query

Software: Aix 6.1 Oracle 11g Installation Process 1. Aix Installation Put it into the CD, start the system, hear a beep, speed at 5, then select the language, enter the menu, select a new installation. Wait ...... 2. Install ssh Remote