Database Administrator

MySQL supports unidirectional and asynchronous replication. During the replication process, a Linux server acts as the master server, and one or more other servers act as slave servers. The master server writes updates to the binary log file and

When using exp to export data in Linux: Connect to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-ProductionWith the Partitioning, OLAP and Data Mining optionsThe ZHS16CGB231280 Character Set and AL16UTF16 NCHAR character set have been

Informix was previously installed in RHAS4, but the idea is vague. Today, we have to install it again. The installation process is listed below to be noted. 1. Create an informix user.Groupadd informixUseradd-g informix 2. Log On As the root user

1. The simplest is to read data that requires consistency from the master database. However, this method is obviously not feasible for applications with large data volumes. 2. the synchronous replication model is used. MYSQL provides a synchronous

Solution to port 80 occupation after Oracle installation: Modify two files in the oracle \ Apache \ conf directory: httpd. conf, httpd. conf. default: Change the port in the file from 80 to 18001 to change the application port of Apache to port 1800

Oracle SQL Developer was often used for simple database operations on Windows PC. This is a JAVA application, and it should obviously be able to run on the newly installed Ubuntu 8.04. It was only installed today that it still takes some effort to

Installation environment: Ubuntu Linux 1. Install JDK first 2. Install MySQL JDBC driver Connector/J (1) Search for Connector/J in the new software management package of Ubuntu (2) Find and install (3) Find the mysql-connector-java-n.n.n file

Public Network: provides external services for connecting clients, application systems, and databases. In addition to database maintenance, users seldom directly connect to the database,A common practice is to connect a user to a database through

In the execution of related SQL statements, the process in mysql is prone to some words similar to file temp, which tells us that our host SQL adopts file Sorting and other operations, this may greatly affect the efficiency of the result set to be

Test environment: DB: 11.2.0.3, 10.2.0.4 OS: RHEL 4.8 Migrate the stored outline data in Oracle 10 Gb to 11 GB 1. Export the data in the test table [Oracle10g @ rhel4 SQL] $ expdp scott/oracle tables = test1directory = testdumpfile = test1.dmp;

Use shell scripts for log analysis. to store the analysis results directly to the mysql database, execute mysql statements in the shell script. Method 1 Save the statements to be executed in each step to tmp. SQL. Mysql-u uname-p pwd Method

We recommend that you change the undo_retention parameter when installing the Oracle software. We recommend that you change the default value of 900 to 10800 seconds, that is, 3 hours; alter system set undo_retention = 10800 scope = both; A part of

For DBAs, it is common to create table. Although this method is simple, negligence can easily lead to unexpected problems. I encountered such a problem a while ago. Because the original TABLE is cloned and the data is stored in different tablespaces,

When a frequent commit/rollback or disk I/O problem occurs and a large number of physical read/write contention occurs, we will often see that the LOG FILE SYNC wait event appears in TOP EVENTS, the metrics for evaluating log file sync wait events

I recently started to study MySQL and MongoDB and found that there is not much information in this area. In particular, there are too few articles on ideas. Some articles on comparative testing are basically blind tests. The testing methods are

1. Create the path to save the backup file/mysqldata # Mkdir/bak/mysqlbak 2. Create the/usr/sbin/bakmysql file. # Vi/usr/sbin/bakmysql. sh 3. Write the following script: NOTE: If your mysql password contains special characters, such! @ #, You need

1. First fill in the database connection string in Webconfig 2. Step 2: Create a page and add the following code Public partial class WebForm1: System. Web. UI. Page{ /// // Connect to the database /////////////////////// ////////String oraclestr =

A few days ago, my colleague sent an SQL statement saying that the update operation was very slow. I checked that the data volume was not large. Check the execution plan and find that the execution path is incorrect. Why is the execution path

In mysql, when the delete operation drops tens of millions of data records, the table may be locked, and the mysql server may be under great pressure. This is an unavoidable problem in mysql. It can be said that it is insufficient in dealing with

It is not a labor-saving task. If your MySQL version is 5.1.7 and earlier than 5.1.23, you can use the following simple method:RENAME {DATABASE | SCHEMA} db_name TO new_db_name; However, this method is not reliable and may cause data loss. It is not