Database Administrator

MySQL Databases can not only be joined between tables, but also can be joined by themselves. This function is quite comfortable. Let's take a look at how to make the table join itself in mysql.Create a table in MySQLCreate table d(Id int (10)

During program debugging, one way is to start from the first line, which is very hard (for example, the program source files are too many or compiled or encrypted ). The other method is to check from the back. The last write is the DB, so we start

Oracle 10g installation error record 1 in linux 5: INFO: mv-f/oracle/app/product/10.2.0/db_1/bin/ctxlc/oracle/app/product/10.2.0/db_1/bin/ctxlcO INFO: mv ctxlc/oracle/app/product/10.2.0/db_1/bin/ctxlc INFO: chmod

Because Red Hat enterprise linux 5 comes with a mysql, When you install a new mysql, an error is prompted, such:Error: Failed dependencies: MySQL conflicts with mysql-server-5.0.77-4.el5_4.2.i386 Rpm-qa | grep mysql can see the installed mysql.

When installing Oracle on Linux, the following errors are often reported: You cannot use the command/usr/X11R6/bin/xdpyinfo to automatically check the display color. Check whether the DISPLAY variable is set. You can use the following command to

Because of the differences in Linux versions: the locations and names of automatically started shell scripts are also different. in linux versions such as RedHat and red flag, the startup scripts are placed in/etc/rc. in the d directory, the name is

Ora-01450 is an error that may occur during index maintenance. First, let's take a look at the relevant information of 01450 through oerr: SQL> ho oerr ora 0145001450,000 00, "maximum key length (% s) exceeded"// * Cause:// * Action: Haha, Oracle

Solve the libpthread. so.0 problem in Oracle 10gRAC InstallationI. Problem The CRS of 10.2.0.1 encounters the same problem in the following situations on linux5:1. rootOracle CRS stack installed and running under init (1 M)Running vipca (silent) for

Group by function of Oracle The test process is as follows :--- Rollup: Details and summary of employees' salaries in each department for reference.Select t. dept_id, t. dept_name, sum (t. salary)From qcfang. test1 tGroup by rollup (t. dept_id, t.

Introduction: Database suddenly reported: ORA-01654: unable to extend index BO. INDEX_indexname by 311072 in tablespace error. There is only one reason to check the Internet, which is to increase the size of tablespace. because the tablespace of the

MySQL master-slave synchronization setup Master database: IP: 192.168.18.204 Edit/etc/my. cnf file to open log-bin Vim/etc/my. cnf Log-bin =/application/mysql/data/mysql. bin Server-id = 1 View: Log_bin should be in the on status [Root @

I. Principle of MySQL master-slave Replication What is mysql master-slave Replication Mysql supports several different forms of replication, such as single bidirectional, chained cascade, and asynchronous replication. During the replication process,

Oracle provides the custom type function. You can define the Record and Table based on your own situation. Record data storage is a Record, A record Table is used to store multiple records. If the Record data type Record is a one-dimensional array,

Remote settings of MySQL Databases in Linux 1. Start the service and log on[Root @ localhost ~] #/Etc/init. d/mysqld restartStopping mysqld: [OK]Starting mysqld: [OK][Root @ localhost ~] # Mysql-u root-pEnter password:Welcome to the MySQL monitor.

Data Guard Services   The following three parts constitute Data Guard's log Data transmission, log Data application, and change the database role: A), log transmission Services (Redo Transport Services) B) log application service C) role conversion 1

1. After reading the introduction of MemSQL, it took several minutes to browse the website, Read getting started, download, install, and start it. MemSQL http://memsql.com/ Its publicity Slogan is the world's fastest database. your data. ACCELERATED.

Because the identifier of the business table is not added during data conversion, multiple processes must perform operations on the same table to improve the update efficiency. 1. Write the corresponding stored procedure: Create or replace procedure

1. Download the Installation File Use the installation package 10201_database_linux32.zip and log on as the root user. 2. Check whether the system resources and environment meet the installation conditions. Grep MemTotal/proc/meminfo: the memory

Today, we used the stress test provided by hbase to stress down our hbase cluster. Cluster configuration: master 8 CPU * 32G + 3 8 CPU * 16G Parameter configuration. The zookeeper and hdfs configurations are modified. Test method: Hbase org.

1. log on to the ASM instance and check whether the ASM disk is correct.[Oracle @ rhel5 ~] $ Export ORACLE_SID = + ASM[Oracle @ rhel5 ~] $ Sqlplus/as sysdbaSQL> select name, state from v $ asm_diskgroup; NAME STATE--------------------------DG1