Database Administrator

When the database operates on a small amount of test data and a large amount of data, the performance is very different. Generally, in the early stage of the development process, people do not pay attention to the database performance. However, with

MySQL4.1 is an Alpha test version, which is not created as a dummies installer and may be inconvenient. However, I like it very much.Distribution of compressed packages: The following describes how to install and upgrade the package 3.23.49. I. New

I. data definition language)A document language is a language defined for the format and form of a document. It is the first thing that every database needs to create, the table relationships, column primary keys in the table, and the reference

Oracle claims that the installation of the Oracle9i database in Linux requires at least MB of memory and at least 1 GB or two times of memory swap space. For servers with a system memory larger than 2 GB, the swap space can be between 2 gb-4gb. If

My current project contains a table with 62 million rows and more than 500 columns. The data comes from outside SQL Server. The tables they arrive at have a primary key, and all the remaining columns are saved in varchar (50) format. Problem Solving

1. RedHat AS4 system installation:Disk Configuration:Device type size/Ext3 39911Swap 1024Basic Network Configuration:Etho IP/Gateway: 199.0.0.230/255.255.255.0Host Name: linuxsvrGateway: 199.0.0.1Primary/secondary DNS:

If the table file or index file in mysql is corrupted, the error code 144,145 is displayed when you operate on the table. You can fix the error as follows:(1) Use repair table table_name to modify the mysql command line;(2) fix the problem in the

There are a lot of Oracle10g documents searched online. I have sorted them out and hope to give them a reference.Configure the environment RedHat4.2 cpu: p42.8 dual-core memory 1g NIC: realtek RTL8169/8110 depressed NicDisk size: 10 Gb dual-system,

Note that the mysql rpm package can be successfully installed on the linux Personal Edition, but installing mysql on enterprise as4 is a little troublesome. Even if it is installed, there are problems. Therefore, I personally recommend that you

1. download the relevant package (the source package must be used)Mysql-5.0.22.tar.gzIi. Run configure. /Configure -- prefix =/data1/zhangsc/local/mysql -- with-mysqld-user = zhsc -- with-unix-socket-path =/data1/zhangsc/local/mysql. sock --

Oracle Database serviceAn Oracle database is represented to clients as a service; that is, the database performs work on behalf of clients. A database can have one or more services associated with it. Oracle connection descriptor connect descr

I. How to start mysql in Ubuntu:/Etc/init. d/sudo mysqld 2. Add a userBin> mysql-u rootMysql> grant permission 1, permission 2,... Permission n on database name. Table name to user name @ user address identified by 'Connection password '; Permission

-- MySql, paging -- Select * from biaoming where tiaojian limit num1 (start), num2 (size) -------- Oracle paging, keyword rownum ---- Select ename, rownum from emp; Select ename, rownum from (select * from emp ); ---- Layer-3 filtering, High

Connect by is used in structured queries. Its basic syntax is:Select... from tablename start with cond1Connect by cond2Where cond3; Example: Select * from classStart with parentid = 27362Connect by prior id = parentid Simply put, a tree structure is

1. Oracle tracking File There are three types of Oracle tracking files: One is the background alarm log file, which records the activity of background processes during database startup, shutdown, and running, such as creating tablespaces, creating

About autonomous transactions resolve the trigger resulting in "ORA-04091: trigger/function cannot read it" unfeasible verification. Some people often ask this question: "There is A problem where Table a has four fields: A, B, c, and d, modify the

Lab instructions 1. In non-archive mode: SQL> archive log listDatabase Log mode non-archive ModeDisable automatic archivingArchiving end point USE_DB_RECOVERY_FILE_DESTOldest online log sequence 2491Current Log sequence 2493 Use the sys user to

Estimate the index size before creating an Oracle Index Estimate the size of a field in a table before creating an index. The best way is to create an index in the test database for prediction. If no test environment is available, you can use

Call path: Stored Procedure-call function initialization variables in TYPE-stored procedure call specific log operations-call TYPES to implement specific Member implementations in body type bobies-call common Member the member stored procedure is

Scenario: If the storage media is damaged and the control file is lost, you need to replace the hard disk and recreate the control file.(1) modify the initialization parameter control_files to change the location of the control file.SQL> ALTER