Database Administrator

In Oracle 11g, you can use the REGEXP_COUNT function. REGEXP_COUNT returns the number of times the mode appears in the source string, which is used as a supplement to the REGEXP_INSTR function. Note that although COUNT is a set function that

I. rollback segment OverviewRollback segments are used to store values before data modification (including locations and values before data modification ). The header of the rollback segment contains the information about the transaction in use. A

1. Install the compiling environment Uname- Linux ha01 2.6.18-194. el5 #1 SMP Fri Apr 2 14:58:35 EDT 2010 i686 i686 i386 GNU/Linux Yum-y install gcc Yum install-y gcc-c ++ 2. mysql compilation and Installation [Root @ ha01 local] # tar-xvf mysql-5.1.

#/U01/app/Oracle/oraInventory/orainstRoot. shChanging permissions of/u01/app/oracle/oraInventory to 775.Changing groupname of/u01/app/oracle/oraInventory to oinstall.The execution of the script is complete#/U01/app/oracle/product/10.2.0/db_1/root.

DBMS_Job package usageIt contains the following sub-processes:Broken () process.Change () process.Interval () process.Isubmit () process.Next_Date () process.Remove () process.Run () process.Submit () process.User_Export () process.What () process.1,

For details about the process, refer to the instructions on the official website. system environment: Uname- Linux higkoo 2.6.18-194. el5 #1 SMP Fri Apr 2 14:58:14 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux Cat/etc/issue CentOS release 5.5

// DataA B C------A1 b1 c1A2 b2 c2A3 b3 c3// Result:Row col value----------1 1 a11 2 b11 3 c12 1 a22 2 b22 3 c23 1 a33 2 b33 3 c3--With tb (Select 'a1' a, 'b1 'B, 'c1 'C from dual union allSelect 'a2 ', 'b2', 'c2' from dual union allSelect 'a3 ', 'b3

I. Permission classification:System permission: The system specifies the user's permission to use the database. (System permissions are for users ). Object permission: the access permission of a certain user to tables or views of other users. (For

More than one million new data records are added each month, and two major data tables (test_ad, test_pd) need to be processed on a regular basis to move data other than the current month to the historical table for storage The data operation stored

1. What are bad database blocks?First, let's take a look at the format and structure of the database block:The data block of the database has a fixed format and structure, divided into three layers:Cache layerTransaction layerData layer When we read

// We all know that the wm_concat () function has the function of connecting strings,// The following is an instance:With t (Select 'A' well number, to_date ('1970-1-10 ', 'yyyy-mm-dd') report date, 'excellent 1' working condition from dual union

V $ SESSION In this view, each session connected to the database instance has a record. Including user sessions and background processes such as DBWR, LGWR, and arcchiver. V $ common columns in the SESSION V $ SESSION is the basic information view

// Requirement:// Query the information entered when the user is not on a business trip// Analysis:// Subquery: We can explicitly query the user IDs and time of information entered during a business trip.// Master query: we retrieve information from

Environment: Oracle 10g, pl/SQL developer 714 Problem: After a beginner installs a local oracle, he does not know which operations can be performed to connect pl/SQL developer to the local oracle. After installing oracle, pl/SQL developer cannot

#! /Bin/sh# Define the strcture of tableTABLE = "(username char (50) not null, password char (20) not null, uid char (10) not null, gid char (10) not null, maildir char (100) not null, domain char (20) not null, active char (1) default '1 ');"#

Select ID, name, zi, hao into outfile "zuozhe.txt" fields optionally enclosed by '"" 'terminated ',' From gushizuozhe Load data infile "zuozhe.txt" into table gushizuozhe fields optionally enclosed by '\ "'terminated ',' (ID, name, zi, hao ); Grant

SQL> desc v $ databaseIs the name empty? Type-------------------------------------DBID NUMBERNAME VARCHAR2 (9)CREATED DATERESETLOGS_CHANGE # NUMBERRESETLOGS_TIME DATEPRIOR_RESETLOGS_C NUMBERHANGE #PRIOR_RESETLOGS_T DATEIMELOG_MODE VARCHAR2

Help colleagues debug the Code: $ SQL _insert_user = sprintf ("INSERT INTO cc_user ('CC _ id', 'name', 'Password') values (: cc_id,: name,: password )"); The SQL statement syntax is incorrect and the insert operation cannot be performed. You can

After Oracle 10.2.0.1 is upgraded to 10.2.0.4, an error occurs in the EM console. This is because the authorization of the enterprise manager database control component and the CA certificate has expired. The official solution is to apply Patch 83502

I have known the MySQL command (command) Auto-completion function in the past few days (MySQL has been used for several years, but now I know it, I am so embarrassed) But it is not enabled by default. To enable this function, you can Vi/etc/my. cnf [