Database Administrator

Finally, I learned to perform some operations on Oracle using commands in Linux. Take the following notes: Oemapp dbastudio open the Enterprise Manager GUI Open the graphical interface of the enterprise manager on the opemapp console (same as the

Latch indicates the locking mechanism that occurs when processing data between running processes of the Oracle database. Lock, which indicates the differential locking mechanism when concurrency occurs between specific objects in the oracle

A friend asked me how to create a database in Oracle? What is the difference between Oracle and other databases? He has too many problems, and I think his simple explanation can satisfy his curiosity about Oracle, so I wrote this article. (Ps: the

When building a web application in Linux, You need to remotely access the MySQL database. We do not recommend using root in Linux to log on, but to add new users. 1) Log On As A root user# Mysql-u root-p 2) Insert a new user, host: %; user: jason;

In practice, you sometimes need to modify the user name, and the common practice is the exp imp method. If the data volume is large, the exp imp method will waste a lot of time, the following describes how to modify the user name by modifying the

First, go to root mode to download 3 Software Term-Readline-Gnu: http://search.cpan.org/dist/Term-ReadLine-Gnu/ IO-Tty: http://search.cpan.org/dist/IO-Tty/ Uniread: http://sourceforge.net/projects/uniread/ Run tar-xzvf... with the root account

Recently I encountered a problem when using MySQL. The like Query always came out with something strange, which is not consistent with the things behind like. I checked it and finally solved it, the following method 4 is used. If you are interested,

As we all know, Oracle database tables are stored in tablespaces. Theoretically, a table can be placed in any tablespace. However, in practice, database engineers tend to be less casual in terms of performance and security. Before creating a

For DEV and UAT environments, databases must be in archive mode, but do not need to be backed up. Therefore, the constant increase in archive archiving logs results in a large amount of disk space consumption. In this case, you can use a shell

Environment: OEL + Oracle 11.2.0.3 Change the dbstart file under $ ORACLE_HOME/bin [Oracle @ Seven bin] $ vi dbstart Find this paragraph at the frontend # First argument is used to bring up Oracle Net Listener ORACLE_HOME_LISTNER = $1 // Set

Before Oracle9i appeared, you can only re-define the table by moving or exporting and importing the table. Therefore, the table redefinition process may be quite long or offline, during this period, the application will fail to operate on the table.

The purpose of Flashback is to roll back the data if you have misperformed the data and submitted it. Some people may say that the backup can be used to restore the system to a previous error, but the correct operation data is also lost. The only

The first thing to note is that a ORA-01555 error is a "secure" error that will not cause data loss or corruption, but will make the query that receives the error Unable to continue, in the daily maintenance of the database, if only one or two

Script Function One-click installation script for a single redis instance Notes 1. Applicable only to Linux/CentOS 64-bit 2. Networking is required during installationStep 1. download and install the libunwind package (TCMalloc dependency package) 2.

Full table scan is a common method for accessing database tables in Oracle. As soon as you see the full table scan in the SQL statement execution plan, you have to consider repairing it. The existence of full table scan does have room for

1. scenario: the mysql database is on the slave machine, the slave machine is on the LAN, the ssh host is required, and then the ssh slave machine (the slave machine) is on the client machine) similar to the following Architecture     As a

Constraints are used to ensure the integrity of database data. In Oracle databases, constraints, triggers, and application code (process, function) can be used to achieve data integrity, because constraints are easy to maintain and have the best

1. Estimate the execution Plan-Explain Plan The Explain plan uses an SQL statement as the input to obtain the execution plan of the SQL statement and store the execution plan output to the schedule. First, add explain plan for before the SQL

This problem is found in a database in the customer environment. At that time, the customer asked for help, the database status is not normal, connected to the database can not operate normally, and sometimes error ORA-12537 error. ORA-12537: TNS:

I saw an article: Using instr in the Oracle database instead of like (see). I am very skeptical after seeing it. The following is a simple test I did to compare and verify the original article.1. Before creating an index SQL> select count(1) from t;