Database Administrator

View the current MySQL encoding: Mysql> show variables like \ '% character % \'; + -------------------------- + ---------------------------- + | Variable_name | Value | + -------------------------- + ---------------------------- + |

First, we will give an example by PAGE: Find the records from the first row to the Tenth row! Select c. * from (select a. *, rownum rm from oper_log a) c where c. rm between 1 and 10  Note: rownum is a pseudo column, which means a column that does

One of the representatives who used NoSQL in the project years ago, MongoDB, summed up some experiences on Weibo. I would like to share with you here. Refreshing use of MongoDB in development MongoDB is a # NoSQL # database suitable for PHP

1. Three types of Oralce logon authentication refer Operating system verification-my computer-management-local users and groups-group ora_dba Password File to verify that _ PWDorcl. ora under the installation directory of oralce is the

In the Oracle world, there are three types of data: undo, redo, and data. Redo is a mechanism generated by "no loss of committed transactions" to serve two types of scenarios: instance recovery and media recovery. Instance recovery objective: to

Recently, I wrote a tutorial to implement automatic and timed backup for MySQL in Linux for later reference. I would like to share it with you. If you have any questions, please try again. The premise is set to 00:00 in the morning, so that the

Theoretical analysis: 1) server process searches buffer cache for the block to be updated by update (also known as buffer in memory). If no block is found, it reads the buffer cache from disk. 2) server process constructs a group of change vectors

There are two origins:1) Frequent redo records2) server process generates a small amount of data each time. If the redo log file generated each time requires a large number of highly concurrent SPSS to write the redo log file, there are two problems:

For cainiao, I would like to explain [install mysql]. It is a general term to use the mysql database on linux, but it is unclear how mysql runs. In fact, mysql is divided into mysql server and mysql client. Therefore, these two [software packages]

The log archiving mode of Oracle can effectively prevent instance and disk faults and is indispensable for database fault recovery. Because the initial installation mode of oracle is not the archive mode, therefore, you need to set it to archive

Today, the undo tablespace of a database on the development side does not know who has set it to auto scaling. What is called House leakage is that the development staff ran a huge task today, then the direct consequence is that the undo tablespace

This article describes how to install the OracleDatabase 11g Release 2 64bit database on the 64ora17 64bit system. Assume that you have installed the 64ora17 64bit operating system and the swap partition is 2 GB, linux security is disabled and the

This article describes how to use vmware server in Red Hat 5.5 to install Oracle 10g RAC (OCFS + ASM). This article assumes that your RHEL5 has been installed, the specific configuration and installation process of Linux are listed below. I.

Here we briefly describe two important parameters in the management process: DYNAMICPORTLIST: Specifies the ports that Collector can dynamically allocate.If a firewall is being used at an Oracle GoldenGate target location, additional ports

Environment:OS: Red Hat Linux As 5DB: 11.2.0.1 Today, we found that the data was written to the table of the master database. After switching logs, we found that the data was not transmitted to the slave database. The following error is reported

After installing Oracle 11g rac. the scanip is configured in ora, but it cannot be accessed. The error is that the target host does not exist. It has been tossing for a long time and I have not figured it out. Later I found that local_listener is

INACTIVELog corruption SQL> alter system switch logfile;  System altered. View the log status SQL>Select * from v $ log;   GROUP # THREAD # SEQUENCE # bytes members arc status FIRST_CHANGE # FIRST_TIM -------------------------------------------------

Check System Environment Grep MemTotal/proc/meminfo# Check physical memory Grep SwapTotal/proc/meninfo # Check the swap space Df-k# Checking Disks Environment required for installing OracleYum install-y binutils compat-db compat-libstdc ++

From MySQL5.6, a new parameter innodb_page_size can be set to 8 K and 4 K for Innodb data pages. The default value is 16 K. This parameter must be added to my. cnf at the beginning of initialization. If a table has been created and modified, an

Special reminder before backup: 1.In the backupMySQLDatabaseMy. cnfFile,RequiredDatadir = {PATH },Otherwise, the path of the backup data cannot be found.. 2.During the backup processINNODBAfter the data file is backed up, the entire database is