Database Administrator

Looking at the current commercial database market, it is called a mass cut-off. Since the relational model was proposed in 1970s, it has been quickly adopted by commercial database systems due to its outstanding advantages. According to statistics,

By searching for materials on the network and trying on your own, I think the following system parameters are critical:(1) back_log:The number of connections that MySQL can have. When the main MySQL thread receives a lot of connection requests in a

1. install LINUXI installed LINUX 4.4 compiled by Oracle.1. If the most important role of this server is to install Oracle, allocate a file system directly to Oracle. For example:/Boot 100 M,/15G,/swap 2G,/opt 20G (ORACLE programs will be placed in

At the same time, the online access volume continues to increase. For servers with 1 GB of memory, the server even crashes every day or gets stuck from time to time. This problem has plagued me for using MySQL for more than half a month. scalable

When installing Oracle in the Red Flag DC 5.0 Standard Edition or Red Hat as 4u2, A compat-libcwait-2.0-2. i386.rpm package,In earlier versions (now this package has solved this problem, * http:// In

Speaking of databases, most small and medium-sized enterprises use SQL server and MYSQL. SQL SERVER is developed by Microsoft. It works very well with IIS and ASP. However, SQL SERVER is charged, while MYSQL is completely free. On the one hand, it

Because the customer's database is the connector source code package of mysql, it took only a few days to find the package. The mysql official website did not find the package. They only provided the version of Mysql4.1 before, and none of the

The following describes how to back up a DB2 database: Operate Under db2inst1. Run the following command in the current directory where you want to save the data: $ Db2stop force (stop database) $ Db2start (start database) * Run the following

The two servers are both linux systems. It took me a lot of time to move the data in the database to the new server (new_server) from the old server (old_server), but I finally succeeded. Mysqldump usage: operate in the mysql/bin directory 1.

Install MySQL Sudo apt-get install mysql-server This should be very simple, and I don't think there is much problem with the installation, so I will not talk about it much. Next we will talk about the configuration in Ubuntu. Configure MySQL

Sqlplus scott/tigrt @ orcl -- ConnectionConn/as sysdba; -- Create a userCreate user zhaoIdentified by zhao123/ -- AuthorizationGrant dba to zhao; -- Create a tablespaceCreate tablespace OADatafile 'e: \ Oracle \ lession1 \ OA. dbf ';Size 20

Fault description: the listener can be started normally, but neither instance can be listened [Oracle @ L-DB-100-17 ~] $ Lsnrctl status   LSNRCTL for Linux: Version 10.2.0.4.0-Production on 2002 14:29:33   Copyright (c) 1991,200 7, Oracle. All

1. LogMiner Installation Run the following two scripts as a SYS User: $ Oracle_HOME/rdbms/admin/dbmslm. SQL $ ORACLE_HOME/rdbms/admin/dbmslmd. SQL 2. Use LogMiner Set a required parameter UTL_FILE_DIR = to ensure that oracle users have read and

I will not talk about the principle of DataGuard here. Here I will just talk about the project process I have implemented. 1. Create a database on the physical hostOperating System: RedHat5.4This project installs a primary and a standby. Therefore,

1) install the PostgresQL module:Enter/usr/local/lib: A node_schedules directory is found, which contains the module you installed.Npm install-g node_gypExport $ PATH = $ PATH:/usr/local/pgsql/bin/Npm install pg //-g indicates global 2) connect to

Using shell scripts to monitor and manage Oracle databases will greatly simplify DBA workload, such as common instance monitoring, monitoring, and daily alert monitoring, and database backup, AWR report automatic mail, etc. This section describes

Varchar (n)Variable-length and non-Unicode character data with a length of n Bytes. N must be a value between 1 and 8,000. The storage size is the actual length of the input data bytes, rather than n Bytes. Nvarchar (n)Unicode data with a variable

APIS involved in this article: Hadoop/HDFS: http://hadoop.apache.org/common/docs/current/api/ HBase: http://hbase.apache.org/apidocs/index.html? Overview-summary.html Begin!How does HBase regularly and quantitatively delete records? Use Case

Control File diversification: multiple control files are copied and stored on different disks. 1. Use SPFILE to diversify Control Files 1) View Control File Information and spfile Information05:55:48 SQL> select name from v $

1. What is a High Water Mark )? All the Oracle segments (segments here, for ease of understanding, we recommend that you use segment as a synonym for the table) have an upper limit to accommodate data within the segments, we call this upper limit