Database Administrator

At the beginning of this day, I learned the MySQL storage process. I just downloaded the new technical White Paper of MySQL 5.0 and carefully studied and practiced it. My personal summary is as follows: 1. When creating a stored procedure on the

Oracle provides an interesting connect by clause, which can sort the branches with a family tree structure. It applies to the structure of organizations or companies, financial account code, and so on. To use query traversal, you need to store data

D jango's ORM has a very convenient function. It should also be said to be a very basic function. After you call save () to insert a model to the database, the created auto-increment id is synchronized to the current model. The default return value

Perform SQL tracking in Oracle. It is estimated that most of them will use autotrace in sqlplus or set 10046 tracking. However, if you are debugging an application system, especially the system that opens the connection pool, the above two methods

Oracle function (converts the entire string to uppercase) NLS_UPPER (x [, y]) [Function] returns a string and converts it to uppercase; [Parameter] x struct expression [Parameter] Nls_param (optional) specifies the sort method (nls_sort = ).

MySQL: UTF-8 character set Oracle: Al32UTF8 Steps: 1. Export csv format data from mysql. Set default_character_set = gbk during export; otherwise, garbled characters will occur. 2. upload to the linux Server (oracle Server) and replace \ r \ n

Solution: 1. Stop OEM firstEmctl stop dbconsole 2. Enter the following three paths:$ ORACLE_HOME/jdk/jre/lib$ ORACLE_HOME/jre/1.4.2/lib$ ORACLE_HOME/javavm/lib/ojvmfonts 3. overwrite the following command in each directoryCp font. properties.

Oracle has five constraints. Primary key primary keys constraints, foreign key foreign constraints. Unique constraint, not null constraint, and check constraint. Remember: constraints are for a column. Check constraints: alter table temp add

1. hardware configuration instructions:The swap partition of Fedora 14 must have at least 2048 MB; otherwise, a warning is reported during Oracle installation.2. software requirements1) dependent software packages to be installed or upgraded.Make-3.8

If 32-bit Oracle is installed with a 64-bit operating system or 64-bit Oracle is installed with a 32-bit system, the following error may occur:"Error in invoking target 'client _ sharedlib 'of makefile' $ ORACLE_HOME/network/lib/ins_net_client.mk '.

I. How to expand the linux swap spaceA) Login as the root user B) Type following command to create 512 MB swap file (1024*512 MB = 524288 block size ):# Dd if =/dev/zero of =/swapfile1 bs = 1024 count = 524288 C) Set up a Linux swap area:#

I. hardware configuration IBM3850 (based on the installation environment) 2. Software preparation Linux.x64_11gR2_database_1of2.zip Linux.x64_11gr2_databasesilicate f2.zip FileZilla.exe Iii. FileZilla software installation and configuration 1.

Operating System: CentOS 5.5 (1) install MySQL The most convenient way to install MySQL on this operating system is to use yum for installation: [Root @ localhost yum. repos. d] # yum install mysql-server (sometimes the network is slow, it will take

At work, we found that orcale time formatting is a little different from Java time formatting: For example, in Java, you can write a string in the format of time when the date is changed: SimpleDateFormat sdf = new SimpleDateFormat (); Sdf.

Because apache of this project is only used to download the function and install phpAdmin to find the database, and Mysql 5.6 has been installed before, it is directly installed using the yum command method during deployment. However, when using

Preparations: How to grant the View query permission to other users:   Sys @ ORCL> grant select on v $ paramter toscott; Grant select on v $ paramter to scott * Row 3 has an error: ORA-00942: Table or view does not exist     Sys @ ORCL> grant select

Symptom:After the instance is started to mount, rename datafile reports an error ORA-01511, ORA-01121, ORA-01110SQL>SQL> ALTER DATABASE RENAME FILE '+ DATA/rac/datafile/system.416.833384105' TO '+ TESTDG/rac/datafile/system. dbf ';Alter database

The histogram is useful when the column data distribution is uneven. The query optimizer needs the histogram information to make a correct estimation. There are two kinds of histogram with frequency and height. This article still uses the previous

Today, the leader asked me to install mysql in the production environment using a compilation-free method, so I had the following content. The directory involved in it has been processed. Please modify it as needed! 1. Download the mysql compilation-

1. Full backup database, and the Backup Type is specified as backupset RMAN> backup as backupset database; Starting backup at 13-FEB-14Using channel ORA_DISK_1..... 2. Back up the users tablespace again and specify the Backup Type as backupset. RMAN>